• 
• 


THE  POTATO 


A  PRACTICAL  TREATISE  ON  THE  POTATO, 
ITS  CHARACTERISTICS,  PLANTING,  CUL- 
TIVATION, HARVESTING,  STORING, 
MARKETING,  INSECTS,  AND  DISEASES 
AND  THEIR  REMEDIES,  ETC.,  ETC. 


SAMUELcF^RASER 

Assistant  Agronomist,  Cornell  University 


ILLUSTRATED 


NEW    YORK 

ORANGE    JUDD    COMPANY 
19  10 


COPYRIGHT.  1905 
BY  ORANGE  JUIJD  COMPANY 


Pn'nlfd  inUS.A. 


SB 


To 


3(dme0  ^cott  (Borbon 

WHC?5  LIFE  AND  WORK  ARE  AN 
INSPIRATION  TO  MANY 


IJ84982 


PREFACE 


THK  literature  issued  on  the  subject  of  potatoes 
during  the  past  three  hundred  years  would  form  a  large 
library,  many  works  having  been  published  in  the 
United  States,  the  United  Kingdom,  France,  Germany, 
and  other  countries.  It  is  safe  to  say  that  no  plant  has 
aroused  a  deeper  interest  than  ' '  the  noble  tuber. ' '  Its 
very  existence  to-day  is  largely  due  to  the  efforts  of 
enthusiasts.  Several  of  the  older  writers  were  keen 
observers  and  acquainted  intimately  with  the  history 
and  character  of  the  potato,  and  modern  authors  in- 
clude the  names  of  men  who  are  eminent  in  the 
scientific  world.  The  vast  amount  of  research  and 
demonstration  carried  out  by  the  experiment  stations 
of  this  country  during  the  past  ten  years,  and  the  fact 
that  every  station  has  done  something  in  this  line,  show 
the  breadth  of  the  subject  and  furnish  material  hith- 
erto unobtainable.  The  excellent  research  work  now 
being  carried  on  in  Europe,  especially  in  France,  Ger- 
many, etc. ,  and  more  recently  established  in  Ireland, 
indicates  a  demand  for  more  information  about  this 
crop.  We  feel  that  the  "science  of  agriculture"  is 
a  reality  ;  that,  like  every  past  generation,  we  are  on 
the  eve  of  great  discoveries;  that  something  of  the 
laws  governing  plant  nutrition  and  growth  will  shortly 
be  revealed,  that  we  may  be  able  to  prevent  rather  than 
cure  the  troubles  which  assail  our  plants.  To  be  of 

vii 


viii  PREPACK 

any  use,  scientific  research  must  be  rigidly  accurate  in 
its  observation  and  merciless  to  fallacy  in  logic.  Once 
a  principle  is  proven  it  is  of  no  use  unless  applied,  and 
the  man  to  apply  it  is  the  farmer. 

At  the  present  time  it  behooves  us  to  divest  our- 
selves of  prejudice,  whether  of  tradition  or  custom, 
which  might  tend  to  warp  our  judgment  and  treat  as 
debatable  assumptions  which  long-established  associa- 
tion have  made  shameful  to  doubt,  but  which,  undis- 
turbed, would  make  the  discovery  of  truth  impossible. 
To-day  theories  are  no  longer  revered  because  our 
fathers  believed  in  them.  The  search-light  of  all- 
prying  Science  illuminates  the  whole  field  of  agricul- 
ture, and  has  led  men  to  doubt  and  call  in  question 
even  truth  itself,  in  order  that  they  might  expose  those 
things  which  are  not  true.  It  is  by  this  means  alone, 
by  this  attitude  of  questioning  all  statements  and 
theories,  both  the  truth  and  the  untruth  alike,  that  we 
can  form  a  just  estimate  of  what  is  true.  That  which 
cannot  stand  the  fire  may  rightly  be  esteemed  dross. 

In  this  book  the  endeavor  has  been  to  collect  many 
scattered  facts  from  many  sources,  and  present  these — 
along  with  experience  derived  by  growing  potatoes  for 
several  years,  commercially  and  experimentally,  in  two 
continents — in  the  hope  that  these  data  will  be  of  value 
to  the  reader. 

SAMUEL  FRASER. 

CORNELL  UNIVERSITY, 
Ithaca,  N.  Y.,  1905 


Note.— With  the  exception  of  Figs.  26,  27,  28,  29,  30,  31,  43,  and  44,  which 
were  kindly  loaned  by  the  makers  of  these  implements,  and  those  in  which 
credit  is  given  in  the  text,  all  illustrations  have  been  prepared  by  the 
Author. 


CONTENTS 


CHAPTER  I 

PAGES 

HISTORY  AND  BOTANY 1-7 

CHAPTER  II 
SOME   CONDITIONS  INFLUENCING   GROWTH 

AND  DEVELOPMENT 8-16 

Influence  of  Light  on  Yield,  8;  Amount  of  Mois- 
ture, 8;  Respiration,  9;  Influence  of  Tempera- 
ture on  Respiration,  9;  Influence  of  Temperature 
on  Growth,  10;  Potato  Roots,  10;  Influence  of 
Depth  of  Planting  on  Roots,  15;  Blossoming, 
Tuber  Formation,  and  Hilling,  16. 

CHAPTER  III 
SOILS 17-25 

Best  Soils,  and  Reasons  why  Certain  Soils  are 
Better  than  Others,  17;  Influence  of  Soil  on 
Different  Varieties,  19;  Subsoiling,  20;  Prepara- 
tion of  the  Soil,  21 ;  Surface-fitting  Tools,  23. 

CHAPTER  IV 
ROTATION 26-29 

CHAPTER  V 
MANURING  AND  FERTILIZING 30-50 

Object,  30;  Influence  of  Nitrogen,  31;  Influence 
of  Potash,  32;  Sources  of  Potash,  33;  Influence 
of  Phosphoric  Acid,  34;  Influence  of  Calcium,  35; 
Barn  Manure,  36;  Function  of  Fertilizers,  39; 
Purchasing  and  Applying  Fertilizers,  42;  Value, 
43;  Unit  Value,  44,  Purchasing,  44;  Valuing 
Barn  Manure,  44;  Mixing  Fertilizers,  46;  Ap- 
plying Fertilizers,  48;  Water  Requirement,  48. 


X  CONTENTS 

CHAPTER  VI 

PAGES 

CONSIDERATIONS  OF  SEED 51-69 

Source  of  Seed,  51;  Management  of  Seed  Previ- 
ous to  Planting,  53;  Sprouting  Potatoes,  54; 
Sprouting  Trays,  60;  Whole  vs.  Cut  Sets,  60; 
Time  to  Cut,  61;  Size  of  Seed,  61;  Amount  of 
Seed  per  Acre,  63;  Relative  Value  of  Bud  and 
Stem  Ends  and  the  Middle  of  the  Tuber,  66; 
Viability,  66. 

CHAPTER  VII 
VARIETIES 70-90 

Selecting  a  Variety,  70;  Cooking  Quality  and 
Flavor,  70,  72;  Yield,  70,  74;  Ability  to  Resist 
Disease,  71,  76;  Color  of  Skin  and  Tuber,  71,  76; 
Nature  of  the  Skin,  71,  78;  The  Shape,  71,  78; 
Depth  and  Frequency  of  Eyes,  71,  79;  Time  of 
Maturity,  71,  79:  The  Haulm,  71,  80;  The  Leaf, 
71,  81;  The  Vigor  of  the  Variety,  71,  82;  Second  ' 
Growth,  71,  85;  Trueness  to  Type,  72,  85;  Test- 
ing Varieties.  86;  The  Relationship  of  Variety 
to  Soil,  87;  The  Most  Popular  Varieties,  87. 

CHAPTER  VIII 
PLANTING 91-104 

Distance  Apart,  91;  Depth  of  Planting,  93;  Influ- 
ence of  Depth  of  Planting  on  the  Depth  at  Which 
Tubers  Form,  94;  Influence  of  Depth  on  Quality, 
96;  Date  of  Planting,  96;  Influence  of  Late  and 
Early  Planting,  97;  Methods  of  Planting,  97. 

CHAPTER  IX 
MANAGEMENT  OF  THE  GROWING  CROP.    .  105-110 

Cultivation,  105;  Systems  of  Culture,  106;  Hills, 
106;  Drills,  106;  Level  Culture,  107;  Method  of 
Cultivation  and  Tools  Used,  107;  Mulching,  no. 


CONTENTS  Xi 

CHAPTER  X 

PAGES 

OBSTRUCTIONS  TO  GROWTH  AND  DEVELOP- 
MENT     111-127 

Influence  of  Season  and  Climate,  in;  Weeds, 
112;  Diseases  Due  to  Parasitic  Fungi  and  Bacte- 
ria, 112;  Late  Blight  or  Rot,  112;  Early  Blight 
or  Leaf  Spot  Disease,  118;  Potato  Rosette,  118; 
Scab,  119;  Diseases  in  Storage,  121;  Wet  Rot, 
121 ;  Dry  Rot,  122;  Stem  Rot  or  Bundle  Blacken- 
ing, 122;  Bacterial  Diseases,  122;  Insects,  123; 
Flea-beetle,  123;  Potato  Bug,  124;  Potato  Worm, 
125;  Potato  Stalk  Weevil,  126;  Grasshoppers,  126; 
June  Bug,  126;  Wireworms,  127;  Striped  Blis- 
ter Beetle,  127;  Arsenical  Poisoning,  127. 

CHAPTER   XI 
SPRAYS  AND  SPRAYING    : 128-142 

Fungicides.  128;  Bordeaux  Mixture,  128;  Mixing, 
129;  Testing  Bordeaux  Mixture,  130;  Strength 
of  Solution,  130;  Bordeaux  Dust  or  Dry  Bordeaux 
Mixture,  130  ;  Washing  Soda  and  Copper  Sul- 
phate Mixture,  131;  Benefits  from  Use  of  Bor- 
deaux Mixture,  131;  Time  of  Spraying,  134; 
Number  of  Sprayings,  134;  Insecticides,  135; 
Paris  Green,  136;  Lead  Compounds,  137;  Arsenic 
and  Lime,  138;  Cost  of  Spraying  and  Profits  De- 
rived, 139;  Spraying  Machines,  140. 

CHAPTER  XII 
HARVESTING 143-146 

Digging,  143;  Methods  of  Digging,  143;  Diggers, 
144. 


Xii  CONTENTS 

CHAPTER  XIII 

PAGKS 

STORING 147-152 

Piles,  147;  Cellars,  149;  Construction  of  Cellars, 
149;  Ventilation  and  Temperature,  150;  Losses 
in  Storage,  151. 

CHAPTER  XIV 

PRODUCTION,  TRANSPORTATION,  AND  MAR- 
KETS      153-165 

Factors  Influencing  Farm  Prices,  157;  Modes  of 
Selling,  159;  Local  Markets.  159;  Distant  Mar- 
kets, 160:  Commission  Rates,  160;  Grading,  162; 
Packages,  162;  Barrels,  162;  Bushel  Boxes,  164. 

CHAPTER   XV 

CHEMICAL     COMPOSITION     AND     FEEDING 

VALUE 166-170 

Composition,  166;  Digestibility,  168;  Feeding 
Value,  168;  Cooking,  169;  Uses,  170. 

CHAPTER  XVI 
BREEDING  AND  SELECTION 171-177 

Propagation  and  Breeding,  171;  Selection,  175. 

APPENDIX 179-180 

Spray  Calendar,  178;  Seed  Treatment,  179. 

INDEX   .  181 


ILLUSTRATIONS 


FIG.  PAGE 

Spraying  in  a  New  York  Potato  Field  .   Frontispiece 

2  Copy  of    Engraving  of    the    Virginian    Potato    from 

Gerard's  "  Herbal,"  1636 2 

3  Sectional  View  of  Potato  Flower 4 

4  Tuber,  Showing  the  Arrangement  of  the  Eyes     .     .  6 

5  Potato  Plant,  Showing  Tubers  (Viewed  from  Above)  12 

6  Potato  Plant,  Showing  Tubers  and  Roots  (Side  View)  13 

7  A  Useful  Type  of  Spring-tooth  Harrow 22 

8  A  Disk  Harrow : 23 

9  A  Double-action  Cutaway   Harrow 24 

10  The  Influence  of  Lime  Upon  Potatoes 36 

11  Potato  Tray  for  Storing  and  Sprouting  Seed  ...  53 

12  Potato     Planted     Four    Inches    Deep,    Showing    its 

Growth  and  Development  of  Tubers   .....  55 

13  Seed  Potatoes  Sprouted  for  Use  in  the  Planter  .     .  56 

14  Seed  of  Early  Potatoes,  Sprouted  for  Hand  Planting  56 

15  Seed   Potatoes,  Showing  Weak,  Long  Sprouts  ...  57 

16  Diagram,  Showing   the    Stand  of   Twenty     Plats   of 

Carman  No.  3  Potatoes 68 

17  Diagram,   Showing    the    Stand    of   Thirty-six    Plats 

of  Early  Trumbull  Potatoes 68 

18  Section  of  a  Tuber  of  Poor  Cooking  Quality  ...  72 

19  Section  of  a  Tuber  of  Good  Cooking  Quality  ...  73 

20  Three   Varieties    Differing  in  the  Character   of    Net- 

ting of  the  Skin 77 

xiii 


XIV  ILLUSTRATIONS 

PIG.  PAGE 

21  Three  Favorite  Shapes  of  Potatoes 79 

22  Potato  Plant,  Showing  Upright  Haulm 80 

23  Potato  Plant,  Early  Variety,  Showing  Dwarf  Haulm  92 

24  The  Modern  Method  of  Planting  Potatoes  ....  98 

25  Planting  by   Hand 99 

26  Sectional  View  of  the  Aspinwall  Potato  Planter.     .  100 

27  Aspinwall  Potato  Planter  (Side  View) 101 

28  The  Robbins  Improved  Planter 103 

29  Platform  of  the  Robbins  Improved   Planter      .     .     .  104 

30  Halleck   Expansible  Weeder 107 

31  Five-tooth  Cultivator,  with  Hiller  Attachment      .     .  108 

32  A  Useful  Two-horse  Cultivator 109 

33  One-horse  Spring  Tooth  Cultivator no 

34  Section    of    Potato    Leaf,    Showing    the    Parts    and 

Mycelium  of  Blight  (Phy  top  ht  horn  infeslans)      .     .  114 

35  Maturation   of   a   Spore  -Sac    and    Germination  of   a 

Spore  of  Rot  (P.  infestans) 115 

36  Longitudinal    Section  of  a  Potato  Stalk,  Showing   a 

Germinating  Spore  of  Rot  (P.  infestans)  .     .     .     .  116 

37  The  Germinating  Tube  of  a  Spore  of  Rot  (P.  infes- 

tans) on  a  Leaf 117 

38  Tubers  with  and  without  Scab 120 

39  The  Cucumber  Flea-beetle  (Crepidadera  Epitrix  cucu- 

tneris) 123 

40  Leaflet  of    Potato,  Showing  Over  a  Hundred    Holes 

Made  by  Flea-beetles 123 

41  Sprayed    and    Unsprayed    Portions   of   a   New    York 

Potato  Field 133 

42  A  Suggestive   English  Spraying  Machine      ....  140 

43  The  Reuther  Potato  Digger 145 

44  The  Hoover  Digger 146 

45  Potato  Shovel 147 


ILLUSTRATIONS  XV 

FIG.  PAGE 

46  Storing  Potatoes  in  Pits 148 

47  Showing  the    Distribution    of    Potato    Production    in 

the  United  States  in  1899 154 

48  Showing  the  Distribution  of  the  Area  in  the  United 

States  in    Potatoes  in  1899 155 

49  Grading  and  Barreling  Potatoes  for  Market    .     .     .  163 

50  Potato    Flower,  with    Calix   and   Corolla    Removed, 

Showing  Anthers  and  Stigma 173 

51  Pistil  of  Potato  Flower,  Showing  Parts 174 


ABBREVIATIONS   USED 


U  S.  D.  A.— United  States  Department  of  Agriculture,  in 
connection  with  reports  or  bulletins. 

E.  S.  R.,  V:33— Experiment  Station  Record,  Volume  V., 
page  33.  Issued  by  the  United  States  Department  of 
Agriculture,  Office  of  Experiment  Stations. 

Experiment  Stations  in  the  various  States  are  designated  by 
the  common  abbreviation  for  the  State — as,  "Wis.": 
Wisconsin.  Where  there  are  two  stations  in  a  State, 
the  particular  one  is  designated — as,  New  York  (N.  Y.) 
Cornell.  The  number  of  the  bulletin  follows.  Some 
States  issue  their  bulletins  in  volumes,  thus:  Tenn.  Bui., 
Vol.  XI.,  I.,  p.  116 — Tennessee  Bulletin,  Volume  XI., 
No.  I.,  page  116. 

Pa.  D.  A. — Pennsylvania  Department  of  Agriculture.  State 
Departments  of  Agriculture  are  abbreviated  in  this 
manner. 

Can.  Exp.  Farms  Report,  1901,  p.  117— Canada  Experi- 
mental Farms  Report  for  1901,  page  117. 

Ont.  Agr.  Col.  and  Farm  Report,  1898,  p.  158— Ontario 
Agricultural  College  and  Farm  Report  for  1898,  page 
158. 

Hort.  Trans.,  Vol.  1.— Horticultural  Transactions  of  Eng- 
land, Vol.  I. 

Nat.  His.  of  Car.— Natural  History  of  Carolina.  By  Mark 
Catesby,  F.R.S.  Second  Edition.  London. 

Proc.  Assoc.  Prom.  Agr.  Science — Proceedings  of  the 
Association  for  the  Promotion  of  Agricultural  Science 
(America). 


THE    POTATO 


CHAPTER  I 
HISTORY   AND    BOTANY 

THE  potato  (Solanum  tuberosum') ,  also  called  ' '  white 
potato,"  "Irish  potato,"  "English  potato,"  or 
"round  potato,"  is  a  native  of  the  elevated  valleys 
of  Chili,  Peru,  and  Mexico,  one  form  of  it  being  found 
as  far  north  as  Southern  Colorado.  The  wild  potatoes 
of  Chili  differ  from  the  cultivated  form,  in  that  they 
produce  seed-balls  more  freely. 

Tobacco,  tomato,  egg-plant,  capsicum,  henbane,  and 
belladonna  all  belong  to  the  potato  family,  but  of 
this  large  family  of  1600  species  but  six  bear  tubers. 
Some  of  these  latter — as,  Darwin's  potato  (Solanum 
mag  Ha) — were  thought  to  have  some  value  for  cross- 
ing to  produce  a  blight-proof  new  race,  but  so  far 
success  has  not  been  attained  in  the  latter  respedl.  A 
variety  of  Solannm  commcrsoni,  another  tuber-bearing 
plant,  is  now  being  boomed  in  Europe  as  a  substitute 
for  the  common  potato.  The  Arizona  wild  potato 
{Solanum  jamesii}  has  been  grown  for  many  years  in 
this  country  in  various  places,  but  its  tubers  are  small 
and  of  little  value.  The  Mexican  or  Central  American 
potato  (Solatium  ttiberosum  var.  boreale}  is  found  native 
in  Colorado. 


THE    POTATO 


FIG.   2— COPY    OK    ENGRAVING    OK    THK    VIRGINIAN    POTATO    IN 

GERARD'S  "  HERBAL,"  PRINTED  IN  1636 

(Compare  with  photograph,  Figs.  5,  6.)    In  England  the  name  Virginian 
potato  was  used  to  designate  its  source. 

The  potato  was  probably  introduced  into  that  part 
of  the  United  States  now  known  as  Virginia  and 
North  Carolina  between  the  middle  and  close  of  the 
sixteenth  century.  It  is  claimed  that  in  1586  colonists 
returning  from  Virginia  probably  took  the  potato  with 


HISTORY    AND    BOTANY  3 

them  to  England.  The  Spanish  had  previously  carried 
it  to  Europe.  Gerard's  "  Herbal,"  published  in  1597, 
describes  the  potato,  and  the  edition  published  in  1636 
contains  a  woodcut  representing  the  potato  as  it  ap- 
peared about  three  hundred  years  ago  (Fig.  2).  The 
potato  was  more  readily  appreciated  in  this  country 
than  in  Europe,  and  by  the  year  1722  it  was  a  comm on 
article  of  food  among  the  whites  and  Indians  in  Vir- 
ginia and  Carolina.1  In  Europe,  with  the  exception 
njF_TrpTatxd,  potato  ^rowJTig"  made  little jgrogress  until 
the  middle  of  jhe  eighteenth  century. 

The  potato  {Solanum  tuberosum)  is  an  annual,  but 
is  virtually  perennial  by  means  of  its  tubers.  It  has 
smooth,  generally  solid,  more  or  less  quadrangular, 
herbaceous  stems,  which  often  attain  a  hight  of  two  to 
five  feet.  The  stems  are  often  furnished  with  membra- 
nous wings  at  their  angles,  and  bear  compound  leaves 
formed  of  oval  leaflets,  between  which  are  often  found 
small,  leafy  growths.  The  flowers  (Fig.  3)  are  borne  in 
clusters,  and  have  an  entire,  wheel-shaped,  five-pointed 
corolla,  varying  in  breadth  from  one  to  one  and  a  half 
inches,  and  in  color  from  pure  white  to  purple.  It  is 
often  claimed  that  many  varieties  do  not  flower,  and  of 
those  which  do  a  great  number  never  bear  fruit.  This 
dearth  of  fruit  is  generally  attributed  to  lack  of  pollen. 
In  many  varieties  the  stamens  have  degenerated,  or  do 
not  open  to  let  the  pollen  out.2  Conditions  seem  to 
have  an  influence,  as  a  variety  may  bear  abundance  of 
pollen  and  mature  seed  in  one  district,  but  not  in 
another  in  the  same  year. 


^-" .  His.  of  Carolina,"  by  Mark  Catesby,  K.R.S.,  2d  ed.      «  Halstead, 
..  Assoc.  Prom.  Agr.  Science,  1888,  p.  33,  "  Potato  Flowers  and  Fruit." 


4  THk,   POTATO 

The  idea  is  prevalent  that  potatoes  do  not  bloom  so 
freely  now  as  formerly.  The  facTs  do  not  tend  to  con- 
firm this.  Mark  Catesby,  who  was  in  this  country  in 
1722  and  1726,  wrote  that  "in  Virginia  and  to  the 


HG.   3 — SECTIONAL    VIEW    OK    POTATO    FLOWKR 

(Diagra  m  matte) 

a— Ovary.  *— Ovules,  which  finally  become  seeds,  c— Calyx,  made  up  of 
green-colored  leaves,  d—  Stigma.  The  pollen  attaches  itself  at  this  place. 
^-Style,  down  which  the  pollen-tube  passes  to  the  ovary  and  ovules. 
/ — Petals,  white  to  purple  in  color,  s — Stamens.  The  thick  upper  portion 
bears  the  pollen,  and  is  known  as  the  anther. 

north  thereof,  they  [potatoes]  are  annuals,  and  produce 
no  flowers,  while  in  Carolina  and  the  Bahama  Islands 
they  produce  flowers."  Many  varieties  existed  at 
that  time,  particularly  in  Virginia,  and  five  kinds'  were 
common — the  Common,  Bermudas,  Brimstone,  Cai:  v, 


HISTORY    AND    BOTANY  5 

and  Claret  potatoes.  The  Bermuda  potato  was  the 
only  one  that  had  a  white  flower,  the  flowers  of  all  the 
other  kinds  being  purple.  This  was  the  only  variety 
that  had  a  white  skin,  and  was  white  fleshed.  It  was 
round  in  shape,  more  tender,  and  more  delicate  to  raise 
than  the  others,  and  did  not  keep  so  well.1 

George  Don,  in  1831,  enumerates  several  English 
early  varieties,  and  says  that  ' '  none  of  the  above  sorts, 
when  true,  produce  blossoms."  '" 

At  Wyoming  Experiment  Station,3  in  1895,  out  of 
56  varieties  grown  14  did  not  bloom,  but  in  1896  but  4 
varieties  failed  to  bloom  out  of  56,  and  only  one  va- 
riety, Blue  Victor,  failed  to  bloom  in  one  of  the  two 
years.  In  other  parts  of  the  State  all  the  varieties 
grown  came  into  bloom.  In  New  York,  during  1904, 
the  variety  Blue  Victor  was  profuse  in  its  bloom,  and 
bore  abundance  of  seed-balls.  Out  of  300  varieties  I 
have  followed  closely,  having  grown  many  for  several 
years,  I  find  that  it  is  seldom  that  a  variety  will  not 
bloom  at  some  time  in  its  life,  and  I  am  sure  that  many 
of  the  heaviest-yielding  varieties  bloom  as  freely  as 
those  of  inferior  merit.  At  Wyoming  Experiment 
Station  the  ten  heaviest  yielding  varieties  all  came  into 
bloom  both  in  1895  and  in  1896,  in  experiments  con- 
ducted in  various  parts  of  the  State. 

The  fruit,  or  seed-ball,  is  a  globular  or  short  oval 
berry,  either  green  or  green  tinged  with  violet,  brown, 
purplish,  or  yellowish  in  color,  and  from  three-quar- 
ters to  one  and  a  half  inches  in  diameter.  It  contains 


"  Nat.  His.  of  Carolina,"  by  Mark  Catesby,  F.R.S.,  zd  ed. 
Don's  "  Gardener's  Dictionary,"  1831-8,  Vol.  IV., ^>p.  400-406. 
Wyo.  Bui.  32,  pp.  54-63. 


THE   POTATO 


small  white  kidney-shaped  seeds  embedded  in  the  midst 
of  a  green  and  very  acrid  pulp  (Fig.  3).  These  seeds 
are  sown  for  the  purpose  of  raising  new  varieties. 

The  main  vertical  underground  stem  varies  in  length 
with  the  depth  of  planting./ This  stem  branches  at  in- 
tervals, and  each  branch  enlarges  at  the  end  to  form  a 
tuber  (Fig.  12).  Usually  from  two  to  four  roots  start 
from  the  vertical  underground 
stem  at  the  base  of  each  tuber- 
bearing  branch,  but  roots  may 
start  where  such  branches  are 
absent.  This  characteristic 
growth  may  be  seen  by  grow- 
ing a  potato  in  a  barrel  half 
full  of  soil  and  manure,  and 
watering  it  well;  then,  as  the 
stem  grows,  place  soil  round  it, 
thus  increasing  the  length  of 
the  underground  portion  and 
the  number  of  tuber-bearing 
branches.  The  tubers  may  be 
formed  above  ground,  and 
whenever  they  are  abundant 
in  the  axils  of  the  leaves  there 
are  few  or  none  below  ground. 

Thgjtuber -is  jyi  underground 
stem,  and  the  eyes  on  it  are 
equivalent  tothe_jeaf  butte  on  ^~stem  of  aT  vcnuie 
peacn~orUlanthus.  They  are  arranged  morejjr  less 
spirally  in  both  cases  (FlgT^JT  From  the  eye  aluiia- 
ber  of  buds  may  start;  hence,  in  the  case  of  new  and 
expensive  varieties,  the  tubers  may  be  split  through  the 


FIG.  4— KIDNEY-SHAPED 

POTATO  (Does  Pride) 
Showing  the  alignment  of 
the  eyes,  and  that  the  ter- 
minal buds  tend  to  start 
first.  Note  the  short,  thick, 
desirable  shoots. 


HISTORY    AND    BOTANY  7 

eyes,  if  desired,  and  a  shoot  obtained  from  each  half. 
As  each  shoot  sets  a  root  it  may  be  broken  off  and  trans- 
planted, and  another  may  start.  By  these  means  and 
great  care  a  pound  of  seed  tubers  has  been  made  to 
yield  2,558  pounds  of  potatoes  in  one  season. 


Historical  Note. — The  early  history  of  the  potato  is  obscure. 
The  most  authentic  information  I  have  secured  is  that  Sir 
Robert  Southwell,  the  President  of  the  Royal  Society  of  Eng- 
land, at  the  meeting  held  December  13,  1693,  stated  that  the 
potato  was  brought  into  Ireland  by  his  grandfather,  who  ob- 
tained tubers  from  Sir  Walter  Raleigh,  after  the  return  of  his 
expedition  from  Virginia.  This  was  in  the  year  1584.  It  is 
now  believed  that  Sir  Walter  Raleigh  fitted  out  this  expedi- 
tion, but  did  not  lead  it  personally,  and  never  was  in  Virginia. 

Timbs'  "Curiosities  of  History,"  page  233,  places  the  date 
of  its  introduction  to  the  British  Isles  as  1586. 


CHAPTER  II 

SOME    CONDITIONS    INFLUENCING    GROWTH 
AND   DEVELOPMENT 

IT  is  common  knowledge  that  a  certain  amount  of 
heat  and  an  adequate  supply  of  air  and  moisture  are 
essential  for  plant  growth.  All  plants  that  have  green 
leaves  require  .lighten  addition,  to  enable  them  to  as- 
si  mi  late  carbon  dioxid  from  the  air,  Hi^nriateit  intr>  its 

component  parts,  and    elaborate   th«*    rarhrm    into    SUCh 

complex  substances  as  starch,  sugar,  and  other  carbo- 
hydrates. 

Influence  of  Light  on  Yield.  K.  Pun.noul'  placed 
colored  glass  over  different  potato  plants.  Two  plants 
under  darkened  glass  elaborated  3 1  and  20  grams  of 
starch  respectively,  while  those  under  ordinary  glass 
elaborated  170  and  1 10  grams;  at  the  same  time  plants 
under  normal  conditions  elaborated  223  and  361  grams. 
To  the  favorable  influence  of  abundant  light  this  writer 
attributes  the  large  yield  of  potatoes  in  a  season  when 
the  aggregate  number  of  hours  of  sunshine  is  unusually 
large.  At  Wisconsin  Experiment  Station  coldness  and 
cloudiness  were  believed  to  be  the  causes  of  a  poor 
yield.' 

The  Amount  of  Moisture. — The  amount  of 
water  the  plant  can  obtain  from  the  .soil  is  closely  cor- 


•  K.  S.  R.,  V.,  p.n6.      «  Wis.  Report,  1902,  p.  188. 
8 


SOME    CONDITIONS    INFLUENCING    GROWTH  9 

related  with  the  mode  of  development.  If  the  soil  is 
very  dry,  and  particularly  if  the  tuber  is  cut,  the  seed 
tuber  may  be  so  weakened  by  loss  of  moisture  that  it 
cannot  grow.  If  a  tuber  has  access  to  but  a  small 
amount  of  water,  there  will  be  little  or  no  root  devel- 
opment, with  little  formation,  of  leaf  shoots,  but  tubers 
will  be  formed.  Advantage  is  taken  of  this  fact  when 
small  early  potatoes  are  required,  the  tubers  being 
placed  in  sand,  in  a  cellar,  when  small  tubers  will  form, 
but  none  or  few  leaves.  Under  certain  conditions,  with 
an  abundance  or  excess  of  moisture,  numerous  leaf 
shoots  and  roots  appear,  but  no  tubers.  An  increase 
in  the  supply  of  moisture  in  the  air  has  been  found  to 
favor  the  development  of  leaves  on  the  shoots,  where 
only  scales  were  formed  in  an  insufficient  supply  of 
moisture. 

Respiration.— We  may  say  that  all  plants  breathe 
or  take  in  oxygen  and  give  off  carbon  dioxid.  With 
potatoes  this  is  a  necessary  function,  and  if  checked, 
growth  is  injured.  It  is  probable  that  light  induces 
some  conditions  more  favorable  to  increased  respira- 
tion than  darkness;  hence,  if  the  object  is  to  store  pota- 
toes, it  will  be  better  to  hold  respiration  at  its  lowest 
point  and  keep  them  in  the  dark.  Respiration  cannot 
go  on  witKbutf  force  or  energy,  and  as  this  must  be 
supplied,  at  least  partly,  from  the  tuber,  it  follows  that 
active  respiration  will  be  attended  by  loss  of  weight, 
and  this  goes  on  very  rapidly  when  the  tuber  sprouts. 

If  we  wish  to  "  sprout "  tubers,  the  best  conditions 
for  doing  so  are  still  undetermined. 

Influence  of  Temperature  on  Respiration. — 
All  plants  have  a  range  of  temperature  at  which  ix-spi- 


10  THE   POTATO 

ration  is  normal.  The  minimum,  optimum,  and  max- 
imum temperatures  have  been  ascertained  for  some 
plants.  Young  wheat  plants  will  respire  at  as  low  a 
temperature  as  28°  F.,  or  below  freezing-point.  The 
optimum  temperature  for  wheat  is  about  104°  F., 
while" that  of  potato_jpj_ants  is  about  113°  F.  The 
maximum  for  wheat  is  113°  F.,  while  that  for  pota- 


respires  best  at  about  1 13°  F.,  but  should  the  temper- 
ature go  above  131°  F.,  the  respiration  will  be  some- 
what less  than  before,  and  the  vitality  weakened ; 
hence,  after  a  hot  spell,  when  the  temperature  exceeds 
the  maximum  for  respiration,  it  is  noticeable  that  the 
potatoes  fail  and  become  more  susceptible  to  the  blight 
or  other  troubles,  owing  to  their  impaired  constitu- 
tion. By  selection  we  might  procure  plants  of  greater 
vitality,  capable  of  standing  the  higher  temperatures, 
which  would  enable  them  to  be  better  ' '  disease-resist- 
ers."  Present-day  potatoes  thrive  best  iii.  a  cool 
climate. 

Influence  of  Temperature  on  Growth.— The 
minimum  temperature  for  germination  of  potato  tubers 
is  about  50°  F. ;  hence,  in  the  Northern  States  early 
planted  tubers  make  little  or  no  growth  unless  planted 
shallow,  and  this  is  not  desirable,  except,  perhaps,  .for 
the  earliest  varieties.  It  is  better  to  germinate  the 
tubers  in  the  barn  before  planting,  thus  saving  time 
(sec  Chapter  VI.,  "  Sprouting  Potatoes"). 

Potato  Roots. — Generally  speaking,  far  more  at- 
tention has  been  paid  to  the  stems  and  leaves  of  plants 
than  the  roots,  yet  iu  order  to  cultivate  the  soil  in  a 
rational  manner  it  is  essential  to  know  \\here  the  roots 


SOME   CONDITIONS    INFLUENCING   GROWTH         II 

are,  their  character,  and._requiremen.ts.  Examination 
of  the  roots  of  Early  Ohio  potatoes,1  made  July  5,  1899, 
forty-three  days  after  planting,  about  the  time  the  crop 
received  its  third  cultivation,  showed  that  at  this  time 
there  was  little  growth  of  fibrous  roots — only  the  skele- 
ton system  supplied  with  numerous  delicate  root  hairs. 
The  seed  tuber  appeared  to  be  sound  and  whole,  but  on 
closer  examination  it  proved  to  be  but  a  shell.  Only  a 
few  eyes  on  the  upper  side  of  each  tuber  produced  shoots; 
thus  one  hill  produced  three  stalks  from  two  eyes,  and 
another  had  seven  stalks  .springing  from  five  eyes. 
The  latter  plant  had  more  numerous  but  smaller  roots 
than  the  former.  Twenty-five  small  potatoes  were  set 
on  the  first  plant,  the  largest  of  which  were  the  size 
of  a  large  pea.  At  this  stage  of  development  the  main 
portion  of  the  roots  was  in  the  surface  eight  inches,  a 
few  roots  reached  to  the  depth  of  eighteen  inches,  but 
the  greatest  root  growth  was  in  a  horizontal  direction. 
The  roots  from  each  hill  had  already  met  and  interlaced, 
some  having  reached  a  length  of  two  feet,  the  plants 
being  three  feet  apart.  At  six  inches  from  the  hill  some 
of  the  main  lateral  roots  were  but  two  and  one-quarter 
inches  from  the  surface  of  the  ground,  while  midway 
between  the  rows  their  depth  was  barely  three  inches 
from  the  surface. 

Further  examination  of  Early  Ohio  potatoes  seventy- 
two  days  after  planting,  when  the  tubers  were  nearly 
full  size,  showed  that  the  mamxo^iLgrQ-a£tk  was  in  the 
upper  foot  of  soil  ;  several  of  the  large  horizontal  roots 
were  within  three  inches  of  the  surface,  and  one  was 
but  one  inch  deep.  Some  of  the  vertical  roots  reached 

"  N.  Dak.  Bui.  45,  p.  541. 


14  THE   POTATO 

a  depth  of  two  and  a  half  feet__  The  deep-growing 
roots  are  very  tender  and  brittle  and  easily  broken, 
differing  in  this  respect  from  corn  roots.  The  hori- 
zontal roots  send  out  vertical  branches,  which  often 
descend  to  a  depth  of  two  feet  or  more. 

Shallow  tillage,  such  as  hand-hoeing  without  hill- 
ing, retains  all  the  roots.  Moderately  deep  tillage 
with  a  five- tooth  single.,  horse-cultivator  and  slight 
hilling  destroys  practically  all  the  surface  roots,  and 
undoubtedly  interferes  seriously  with  the  plant's  de- 
velopment ;  while  with  deep  tillage  nearly  all  the  long 
horizontal  roots  are  destroyed,  and  with  them  all  their 
numerous  vertical  branch-roots  with  their  intricate 
s-^  system  of  fibres  and  root  hairs,  by  which  the  potato 
receives  its  food.  :*  In  very  heavy  soils  it  may  be  wise  to 
plant  potatoes  shallow  and  then  hill  them,  but  in  most 
soils  it  is  better  policy  to  plow  deep,  plant  fairly  deep, 
and  give  shallow  flat  cultivation.  With  deep  tillage 
the  roots  nearest  the  surface  were  at  a  depth  of  seven 
inches,  while  in  the  case  of  those  receiving  shallow 
tillage  the  bulk  of  the  horizontal  roots  were  in  the  sur- 
face seven  inches.  The  hilling  covers  the  potatoes  and 
prevents  them  from  sunburning,  and  this  seems-to  be 
all  the  benefit  received.  The  loss  of  joots  is  very 
hurtful,  and  takes  place  at  a  time  when  the  plant  can 
least  afford  to  suffer  injury.  Experiments  conducted 
at  Vermont  Experiment  Station'  show  that  during 
the  last  weeks  of  growth  the  weekly  increase  in  weight 
of  tubers  is  at  its  maximum,  and  that  checks  when  the 
tubers  are  approaching  maturity  depress  the  yield  cor- 
respondingly. 

1  Ver.  Bui.  72.  p.  5. 


SOME   CONDITIONS   INFLUENCING   GROWTH         15 

A  sample  of  Early  Ohio  potatoes  taken  ninety  days 
after  planting,  when  the  vines  were  beginning  to  die 
and  the  tubers  were  nearly  ripe,  showed  that  the  roots 
penetrated  to  a  depth  of  over  two  and  a  half  feet.1  The 
branches  from  the  main  lateral  roots  had  reached  about 
as  deep  as  those  immediately  under  the  hill,  and  the 
soil  was  filled  with  roots  to  a  depth  of  about  two  and 
a  half  feet.  The  system  of  rooting  is  similar  to  that  of 
corn,  but  the  plant  is  not  so  good  a  forager,  and  the 
roots  do  not  fill  the  soil  so  completely;  hence,  plants 
can  be  placed  closer  together. 

Late  ^varieties  have  a  similar  root  system,  but  root 
more  freely,  more  deeply  (a  depth  of  three  and  a  half 
feet  being  common  if  the  soil  conditions  will  permit), 
and  occupy  the  ground  more  completely;  hence,  require 
mofe  room  than  early  varieties. 

At  Cornell  University,  during  1904,  many  potatoes 
had  horizontal  roots  in  the  surface  inch  of  soil.  All 
of  these  would  be  destroyed  by  moderately  deep  tillage. 

Influence  of  Depth  of  Planting  on  Roots. — 
Generally  speaking,  the  new  potatoes  and  the  roots  start 
out  above  the  seed,  although  if  an  under  eye  of  the 
potato  produces  the  shoot  the  roots  and  tubers  may 
develop  at  the  side  of  the  seed.  Depth  of  planting  has 
some  influence  on  the  depth  at  which  the  tubers  will 
form,  and  may  have  some  on  the  roots.  The  question 
deserves  investigation.  Many  plants  prefer  to  send 
out  their  roots  at  a  uniform  depth  below  the  surface  : 
thus,  at  Cornell  University,  wheat,  whether  planted 
six  inches  deep  or  one  inch  deep,  will  send  out  its  per- 


N.  Dak.  Bui.  43,  p.  544. 


1 6  THE  POTATO 

manent  roots  about  one  and  a  half  inches  below  the 
surface. 

Blossoming,  Tuber  Formation,  and  Hilling. — 
Potatoes  are  hilled  about  the  time  they  come  into 
bloom,  and  this  is  the  time  that  tuber  formation  is 
beginning.  The  ancestral  type  of  potato  developed 
seed  about  this  time  and  died  ;  the  tendency  acquired 
by  cultivation  is  to  throw  all  the  reserve  material  into 
tuber  production.  These  reproductive  processes  cause 
a  severe  drain  upon  the  plant's  energies,  and  the  fort- 
night immediately  following  the  blossoming  period  is 
therefore  a  peculiarly  critical  time  for  the  plant,  during 
which  time  its  life  hangs  in  the  balance.  At  this  time 
it  is  subject  to  extreme  heat,  and  may  be  injured;  also 
insects,  fungi,  etc.,  may  attack  it,  and,  to  add  to  its 
troubles,  cutting  off  a  lot  of  its  roots,  either  just  before 
or  about  this  time,  is  no  doubt  the  common  cause  of  a 
decline  from  which  the  plant  never  recovers.  Even 
tuber  formation,  without  the  influence  of  other  agen- 
cies, may  cause  a  plant  to  die.  The  importance  of 
studying  the  condition  of  the  plant  at  this  time  will  be 
appreciated  when  it  is  remembered  that  the  entire  crop 
of  salable  tubers  is  formed  after  this  critical  period  is 
past,  and  full  success  with  the  crop  depends  upon  retain- 
ing the  plant  healthy  for  from  one  to  three  months 
after  the  blossoming  period.  During  August,  in  one 
case,1  the  crop  of  potatoes  increased  at  the  rate  of  over 
50  bushels,  or  over  3,000  pounds,  weekly  per  acre. 
The  importance  of  avoiding  checking  growth  prepara- 
tory to  or  during  such  a  time  is  evident. 


'  Ver.  Bui.  72,  !>•  5- 


CHAPTER   III 
SOILS 

THE  soil  considered  best  is  a  deep,  mellow,  free- 
working  loam,  grading  either  to  a  sandy  loam  or  clay 
loam,  although  the  crop  may  be  raised  on  lighter  or 
heavier  soils,  provided  the  latter  are  drained.  Tile 
drainage  should  be  resorted  to,  if  necessary,  to  reduce 
the  water  table  to  from  3  feet  6  inches  to  4  feet  below 
the  surface. 

Some  reasons  for  selecting  a  light,  sandy,  or  gravelly 
loam  for  the  crop  are  : 

1 .  Such  soils  can  be  worked  early  in  spring,  and  gotten 

ready  for  early  planting,  if  desired  ; 

2.  The  lighter  soil  becomes  warm  more  readily  in  the 

spring  than  a  heavier  soil,  and  germination  of  the 
tuber  and  growth  of  the  plant  proceeds  more 
rapidly  ; 

3.  They  can  be  easily  worked,  and  placed  and  main- 

tained in  good  tilth  without  a  heavy  labor  bill  ; 

4.  The  effects  of  the  manures  and  fertilizers  applied 

are  generally  perceptible  for  a  longer  period  of 
time  than  on  lighter  soils  ; 

5.  The  potatoes  grown  on  such  a  soil  usually  come  out 

bright  and  clean,  smooth  and  of  more  uniform 
size  —  important  factors  when  they  go  on  the 
market ; 

17 


1 8  THE  POTATO 

6.  Light  soils  usually  produce  potatoes  of  better  qual- 

ity, because  they  tend  to  shorten  the  growing 
period  by  cutting  off  the  moisture  supply,  and  thus 
forcing  the  potatoes  to  mature  earlier; 

7.  Those  grown  on  well-drained  sandy  loam  soils  usu- 

ally keep  better  than  those  grown  on  stiff  clay 
soils. 

Aroostock  County,  Maine,  is  famous  for  its  potatoes.1 
Its  soil  presents  a  gently  rolling  surface,  and  is  com- 
posed essentially  of  drift  deposited  during  the  melting 
of  the  ice  after  the  ice  age,  and  resting  on  a  stratum 
of  limestone,  which  in  many  places  comes  to  the  sur- 
face. The  soil  partakes  of  the  general  nature  of  drift 
containing  a  considerable  portion  of  sand  and  the  usual 
amount  of  organic  matter.  It  is  peculiarly  suited  to 
potatoes,  because  it  does  not  pack  after  hard  rains  nor 
during  periods  of  drouth.  Its  open  and  porous  nature 
permits  the  free  development  of  tubers  and  the  ramifi- 
cation of  the  roots.  The  soil  was  originally  covered 
with  a  growth  of  hard  and  soft  woods,  consisting  chiefly 
of  maple,  cedar,  birch,  white  poplar,  spruce,  hemlock, 
and  pine.  The  forest  growth  was  dense,  and  in  clear- 
ing large  quantities  of  ashes  were  produced,  which 
fitted  the  virgin  fields  particularly  for  the  production 
of  large  crops  of  potatoes.  After  a  few  years  of  culti- 
vation, the  crop-producing  power  of  the  soil  showed  a 
diminution,  and  to-day  applications  of  farm  manures 
and  commercial  fertilizers  containing  a  large  percent- 
age of  potash  are  resorted  to.  Analyses  of  Maine  soils 
show  that  they  are  silicious,  contain  considerable  or- 


>  U.  S.  D.  A.,  Div.  of  Chemistry,  Bui.  58,  p.  5-8. 


SOILS  19 

ganic  matter,  and  are  reasonably  rich  in  lime  and  mag- 
nesia, which  seem  to  be  essential  constituents  of  a  soil 
suited  to  the  growth  of  potatoes.  The  potash  is  also 
in  fair  quantity,  but  not  sufficient  to  produce  maximum 
crops.  The  famous  potato-growing  counties  of  Wiscon- 
sin, Portage,  Waushara,  and  Waupaca  had  over  60,000 
acres  in  potatoes  in  1899,  and  these  are  as  important 
to  the  Central  States  as  Aroostock  County,  Maine,  is 
to  the  Eastern  States.  The  soil  is  glacial  drift,  some 
of  it  being  made  up  of  level  deposits  of  sand  and  gravel 
covered  with  a  light  loam.  The  sand  is  usually  un- 
derdrained  by  a  bed  of  coarse  gravel.  Sandy  loams 
prevail.  Clayey  loams  occupy  some  areas,  but  are 
not  prevalent.  The  average  yield  is  100  bushels 
per  acre. 

On  L-ong  Island,  N.  Y.,  the  chief  potato  soils  on  the 
south  side  of  the  island  are  light  silt  loams  underlain 
either  by  gravel  or  sand,  while  gravelly  till  is  the 
main  type  on  the  northern  side.  The  yields  vary  from 
80  to  250  bushels  per  acre. 

The  Influence  of  Soil  on  Different  Varieties.— 
Professor  Buffum,1  of  Wyoming  Experiment  Station, 
reported  on  eight  varieties  grown  on  each  of  two  kinds 
of  soil  represented  on  the  experiment  farm.  The  soil 
and  crops  were  treated  alike.  Plat  i  is  bench-land 
above  the  river,  and  is  a  deep  red  colluvial  soil  con- 
taining little  humus.  Plat  2  is  bottom-land  next  the 
river,  and  is  a  black  soil  containing  a  large  amount  of 
humus. 


J  Wyo.  Bui.  32,  p.  6. 


THE   POTATO 
TABLE  I 


VARIETY 

Plat  i 
Yield  per  acre 

Plat  2 
Yield  per  acre 

Increased  yield 
on  Plat  2 

Lbs. 
q  678 

Lbs. 

23  628 

Lbs. 

Early  Mayflower  
Early  Puritan  

5,060 
2,702 

28,842 
32,340 

22  698 

13,782 
19-638  . 

L,ate  Puntan  
Pride  of  the  West  

i:i578 
5,040 

4  S62 

26,742 
23,322 

7,884 
18,282 
10  938 

White  Elephant 

I  808 

16  182 

Average  

12,885 

26,383 

13.498 

The  figures  taken  collectively  show  the  importance 
of  selecting  a  soil  suitable  for  the  crop  to  be  grown, 
the  yield  being  doubled  on  Plat  2,  while  taken  indi- 
vidually it  is  evident  that  certain  varieties  were  better 
adapted  to  the  environment  than  others.  The  ques- 
tion of  which  variety  will  best  suit  the  environment 
must  be  determined  by  the  grower. 

Subsoiling. — Buffum1,  of  Wyoming,  states  that  sub- 
soiling  may  be  recommended  throughout  that  State  for 
potatoes.  The  cost  of  subsoiling  to  a  depth  of  1 6  inches 
to  1 8  inches  varied  between  $3.00  and  $6.00  per  acre. 
Hays2,  of  Minnesota,  found  it  to  be  expensive  and  not 
profitable  under  most  conditions  in  that  State,  and  that 
it  reduced  the  yields  of  crops  on  land  already  suffi- 
ciently open  and  porous.  In  humid  climates,  if  at- 
tempted, it  is  advocated  that  subsoiling  be  done  in  the 
fall,  to  permit  the  readjustment  of  the  soil  granules 
before  springtime,  so  that  the  moisture  will  be  able  to 
rise  upward  from  the  subsoil,  as  evaporation  takes 


Wyo.  Bui.  41,  pp. 


i;  Hill.  32.  pp.  7, 


"  Minn.  Bui.  68,  p.  609. 


SOILS  2 1 

place  at  the  surface,  and  prevent  the  crop  being  de- 
stroyed by  lack  of  moisture.  Injurious  results  from 
subsoiling  in  spring  have  been  noted,  probably  due  to 
the  working  of  the  subsoil  when  it  was  too  wet.  It 
does  not  follow  that  because  the  surface  soil  to  the  depth 
of  eight  inches  is  dry  enough  to  plow  the  subsoil  will 
be,  and  in  many  cases  the  subsoil  has  been  puddled 
by  spring  working,  and  the  supply  of  moisture  from 
below  more  or  less  completely  cut  off,  with  disastrous 
results  to  the  crop. 

Preparation  of  the  Soil. — The  ideal  crop  to  pre- 
cede potatoes  is  timber,  but  as  no  rotation  comprising 
this  crop  is  in  use,  the  preparation  given  after  timber 
demands  little  attention.  Potatoes  are  more  commonly 
grown  after  potatoes,  corn,  or  after  clover  or  sod.  In 
such  cases  preference  is  usually  given  to  fall  plowing, 
accomplished  during  October  or  November  until  freez- 
ing prevents  further  work.  Deep  plowing  should  be 
done  in  fall,  because  opportunity  is  then  given  for  the 
storage  of  water  in  the  soil  during  the  winter  and 
when  the  thaw  occurs  in  spring.  If  manure  is  to  be 
applied  it  is  spread  before  plowing,  but,  if  rotted,  it  may 
be  applied  later  and  disked  in.  The  depth  of  plowing 
varies  with  the  soil,  probably  six  inches  or  eight  inches 
being  most  common,  although,  if  the  soil  will  permit, 
eight  inches  to  twelve  inches  will  be  better.  When 
soils  are  deficient  in  humus,  it  is  generally  inadvisable 
to  plow  deeply.  The  humus  content  of  such  soils 
should  be  increased  and  the  depth  of  plowing  increased 
correspondingly,  thus  bringing  the  land  into  a  higher 
state  of  production.  In  some  districts  where  the  snow 
covers  the  ground  all  winter  the  land  is  harrowed  well 


22  THE   POTATO 

in  fall  and  left  nearly  ready  for  planting,  thus  facilita- 
ting spring  work.  Where  the  frost  penetrates  deeply, 
or  the  soil  is  apt  to  run  together,  the  land  is  better  left 
rough  plowed  all  winter  and  fitted  in  spring  ;  but  this 
entails  some  loss  of  time,  and  prevents  the  early  plant- 
ing of  potatoes. 

Sometimes  it  is  necessary  to  plow  in  spring,  and  in 
many  cases  it  is  profitable  to  replow  when  a  fall  plow- 


FIG.  7— A  USEFUL  TYPE  OF   SPRING-TOOTHED   HARROW 

ing  has  been  given.  Under  such  conditions  a  depth  of 
not  more  than  six  inches  or  eight  inches  is  advised, 
because  plowing  land  is  attended  by  loss  of  moisture, 
and  in  most  cases  the  amount  of  moisture  held  in  the 
soil  or  supplied  as  rainfall  during  the  growing  period 
is  insufficient  to  insure  maximum  yields ;  hence,  care 
should  be  taken  to  conserve  all  the  moisture  possible 
by  plowing  judiciously,  making  and  maintaining  a 
mulch  of  the  surface  soil,  thus  checking  evaporation, 


SOILS  23 

and  by  enriching  the  soil  in  humus  either  by  manuring 
or  a  suitable  rotation.  Humus  affects  the  physical 
properties  of  the  soil  considerably — among  other  things, 
enabling  it  to  hold  more  moisture  without  injury  to 
the  plants  in  a  wet  time,  and  to  endure  drouth  in  a 


FIG.  8— AN   EFFICIENT   PULVERIZER;   THE   DISK   HARROW 

dry   time.1     Even   where  irrigation   is  practiced   the 
above  factors  cannot  be  economically  neglected. 

Surface -fitting  Tools. — The  Acme  harrow  is  one 
of  the  best  tools  for  making  a  soil  mulch  before  the 
crop  is  planted,  and  in  trials  made  by  Sanborn*  was 
shown  to  be  the  most  efficient  type  of  harrow  for  pul- 
verizing soil.  On  stony  land,  or  where  roots  of  trees 
interfere,  the  spring- tooth  harrow  (Fig.  7)  is  preferred 
for  deep  tillage  of  the  soil,  while  under  other  conditions 


Minn.  Bui.  68,  pp.  576-579.      2  Utah  Bui.  4. 


24  THE   POTATO 

the  disk  harrow.  These  tools  work  deeper  than  the 
Acme  harrow,  and  may  be  used  to  prepare  the  soil  to  a 
depth  of  four  to  six  inches,  which  seems  to  be  as  deep  as 
is  necessary.  Few  farmers  prepare  land  to  this  depth, 
as  it  requires  three  horses  on  a  six-foot  harrow  on  a  loam 
soil.  Two  to  2^  inches  is  more  common.  Harrows 
differ  in  their  action;  thus,  the  spring-toothed  harrow 


FIG.  9      DOUBLE-ACTION  CUTAWAY   HARROW 

and  the  smoothing  or  spike-tooth  harrow  tend  to  com- 
pact the  soil  while  fining  it,  while  the  disk  type  (Figs. 
8  and  9)  and  Acme  harrows  tend  to  lighten  it  and  make 
it  more  open  when  they  fine  it.  For  potatoes  and  corn 
the  latter  are  preferable,  while  for  wheat  the  former. 
Whatever  tool  is  used  the  land  should  be  well  fitted. 
Few  farmers  prepare  the  land  well  enough,  and  many 


SOILS  25 

would  find  it  more  economical  and  profitable  to  spend 
another  week  working  the  land  than  to  rush  the  crop 
into  a  -badly  prepared  seed-bed.  The  soil  under  the 
plants  and  near  them  cannot  be  touched  when  they  have 
been  planted,  while  wide  tools  may  be  used  before. 


CHAPTER  IV 
ROTATION 

IN  some  cases  potatoes  are  grown  continuously  for- 
several  years  on  the  same  soil,  but  a  rotation  of  crops 
is  preferable  for  many  reasons — among  others,  to  lessen 
the  dangers  of  attacks  of  diseases  and  insects,  and  to 
bring  the  soil  into  a  suitable  physical  condition  for 
growing  this  crop.  Some  rotations  suggested  by 
Wheeler,  of  the  Rhode  Island  Experiment  Station,1 
are  as  follows:  three-year  rotation — potatoes,  winter 
rye,  common  red  clover;  four-year  rotation — corn  on 
clover  sod,  potatoes,  winter  rye,  clover.  This  can  be 
made  into  a  five-year  rotation  by  seeding  timothy  and 
redtop  with  the  clover,  and  leaving  the  mixture  down 
two  years,  thus  reducing  the  labor  bill  to  some  ex- 
tent. Trials  of  these  and  other  rotations  were  made 
on  land  so  poor  that  corn  attained  a  hight  of  but  4 
or  5  inches,  while  the  first  crops  of  salable  potatoes 
were  but  65  bushels  per  acre.  During  later  years, 
with  management  similar  to  that  given  the  first  year, 
and  the  application  of  a  similar  amount  of  fertilizers, 
the  yields  ran  up  to  350  bushels  of  salable  potatoes  per 
acre.  A  common  Maine  rotation  is  a  four-year  course 
of  potatoes,  oats,  clover  and  grass,  the  latter  for  two 
years — it  being  noted  that  clover  thrives  on  good  po- 
tato land.  In  deciding  upon  the  rotation  it  is  important 


R.  I.  Bui.  74,  75,  76. 
26 


ROTATION  27 

to  note  the  influence  of  each  crop  upon  the  moisture 
content  of  the  soil  (see  p.  50);  thus,  rye  removes  less 
moisture  from  the  soil  than  wheat.  Oats  draw  heav- 
ily upon  the  moisture  content. 

The  potato  crop  is  not  usually  considered  to  be  a 
heavy  water  consumer.  It  leaves  the  soil  in  a  rela- 
tively moist  condition;  hence,  the  wisdom  of  the  Maine 
four-year  course,  in  which  oats  succeed  potatoes. 
This  course  requires  but  one  deep  plowing  in  four 
years,  that  for  the  potatoes,  and  in  this  it  is  econom- 
ical. Peas  use  a  relatively  small  amount  of  water, 
and  would  leave  the  soil  in  good  shape  for  potatoes. 
In  Wisconsin,1  while  potatoes  grown  in  rotation  yield- 
ed 342.8  bushels  per  acre,  a  crop  grown  on  an  old 
alfalfa  sod  yielded  but  277.7  bushels  per  acre,  al- 
though the  rainfall  was  considered  adequate  to  pro- 
duce a  full  crop.  In  some  cases  clover  tends  to 
leave  the  soil  drier  than  some  other  crops,  and  its 
use  as  the  preceding  crop  for  potatoes  may  be  detri- 
mental. In  most  cases,  however,  a  leguminous  crop 
is  the  best  to  precede  potatoes.  In  Florida2  cow-peas 
preceding  potatoes  increased  the  yield  40  per  cent. 
The  Ohio  Station3  found  that  in  the  three-course  rota- 
tion— potatoes,  wheat,  clover — whenever  good  crops  of 
clover  were  grown  the  economy  of  using  nitrogenous 
fertilizers  for  the  potatoes  was  questionable,  thus  show- 
ing that  a  good  rotation  is  equivalent  to  manuring. 
Plowing  under  a  leguminous  crop  is  held  to  be  good 
practice  on  farms  where  an  adequate  supply  of  manure 
is  not  forthcoming  and  little  stock  is  kept;  thus,  a-t  the 


1  Wis.  Report,  1902,  p.  188.  •  Fla.  Report,  1900-1901,  p.  26. 

1  Ohio  Bui.  125,  p.  132. 


28 


THE  POTATO 


Maryland  Station,1  plowing  under  a  crop  of  crimson 
clover  increased  the  yield  34.4  bushels  per  acre,  or  50 
per  cent.,  and  the  average  gain  for  two  years  was  27 
bushels  per  acre,  or  45  per  cent.;  the  Storrs8  (Connect- 
icut) Station  reports  that  clover  sown  in  corn  at  the 
last  cultivation  had  a  high  value  when  used  to  plow 
under  as  manure  for  potatoes,  even  though  it  only 
attained  a  hight  of  three  or  four  inches ;  in  Germany3 
the  sweet  clover  {Mclilotus  alba)  is  found  to  be  a  valu- 
able green  manure;  while  in  another  German  experi- 
ment,4 where  clover  was  seeded  in  rye  which  was 
grown  for  grain,  the  clover  being  plowed  under  the 
following  spring,  it  was  noted  that  the  yield  of  rye 
was  dimished,  but  the  yield  of  the  succeeding  crop  of 
potatoes  was  increased.  The  yields  of  rye  and  potatoes 
were: 

TABLE  II 


CROP 

Yield  per  acre  of 
rve,  1892 

Yield  per  acre  of 
potatoes,  1893 

Rye  alone  
Rye  alone  
Rye  and  late  sown  red  clover 
Rye  and  early  sown  red  clover 

Bushels         Lbs. 

Bushels          Lbs. 

14                44 

15                       21 
13                       50 

12                35 

289                 35 
296                  15 
330                 25 
43°                 39 

As  green  manuring  for  poor  sandy  land  on  Long 
Island,  N.  Y. ,  Professor  Stone,  of  Cornell  University, 
suggested  sowing  a  bushel  of  cow-peas  and  ten  pounds 
of  crimson  clover  per  acre,  in  July,  with  some  fertil- 


Md.  Bui.  38,  p.  58. 
«.  S.  R.,  V.,  p.  701 


*  Conn.  (Storrs)  Report,  1900,  p.  65. 
«  E.  S.  R.,  VI.,  p.  292. 


ROTATION  29 

izers.  The  cow-peas  were  killed  by  the  first  frost,  but 
the  clover  persisted;  the  crowding,  however,  was  such 
that  the  plants  of  neither  crop  got  too  large  before  be- 
ing plowed  under  the  following  spring.  For  farther 
north  a  combination  of  half  a  bushel  of  buckwheat 
and  a  peck  to  half  a  bushel  of  rye  per  acre,  sown 
together,  has  given  good  results.  Rape  sown  at  the 
rate  of  four  to  five  pounds  per  acre  is  useful.  Other 
crops  will  suggest  themselves.  In  parts  of  New  York, 
especially  on  heavy  loams,  buckwheat  is  esteemed  as 
the  preceding  crop  for  potatoes.  It  crowds  out  weeds 
and  leaves  the  soil  in  excellent  physical  condition. 


CHAPTER  V 
MANURING   AND    FERTILIZING 

LAND  is  manured  and  fertilized  either  to  increase  or  to 
maintain  its  crop-producing  power.  Whether  this  is 
secured  by  the  direct  effect  of  the  chemical  ingredients  in 
the  manure  or  fertilizers,  or  by  their  influence  upon  the 
physical  properties  of  the  soil,  or  both,  is  an  unsettled 
scientific  problem,  but  all  agree  that  under  certain  con- 
ditions the  addition  of  manures,  fertilizers,  and  water 
to  the  soil  is  profitable.  Whether  it  will  be  profitable 
on  a  particular  farm  or  field,  and  the  manure,  fertil- 
izer or  combination  of  fertilizers  which  will  be  most 
profitable  to  use,  are  questions  the  grower  must  settle 
for  himself  by  trial.  No  chemical  examination  of  the 
soil  yet  conducted  has  shown  why  two  soils,  apparently 
identical  in  chemical  composition,  should  not  produce 
similar  yields  of  crops.  Experience  has  shown  that 
the  chemical  composition  of  the  soil  is  no  guide  to  its 
crop-producing  power.  Hence,  all  that  can  be  given  in 
this  chapter  is  to  submit  mixtures  of  fertilizers  that 
are  used  and  the  r61e  the  different  important  ingre- 
dients are  believed  to  play  in  the  plant  economy. 

In  addition  to  water,  which  is  treated  elsewhere, 
four  elements  are  frequently  applied  in  various  chem- 
ical forms  as  fertilizers  —  nitrogen,  phosphorus,  potas- 
sium, and  calcium.  The  potato  through  its  life  re- 
quires liberal  supplies  of  the  first  three  of  these  elements, 
and  its  behavior  in  regard  to  these  is  similar  to  that  of 

30 


MANURING    AND    FERTILIZING  31 

a  shallow- rooted  root  crop.  The  facts  that  the  potato 
is  a  starch-producing  crop,  and  that  its  period  of 
growth  is  through  the  summer  and  extending  well  into 
autumn  must  be  remembered.  In  these  features  it  is 
similar  to  corn,  but  distinctly  different  from  the  cereals 
which  ripen  in  the  summer,  as  it  is  assumed  that  it  is 
able  to  utilize  the  nitrates  and  other  plant-food  liber- 
ated during  the  summer  and  fall.  E.  Hecke'  states 
that  the  demand  for  nitrogen  is  especially  strong  dur- 
ing the  first  half  of  the  vegetative  period,  while  the 
demand  for  potash  is  greatest  during  the  second  half 
of  the  growing  period,  and  that  potash  aids  in  the  for- 
mation of  starch,  and  especially  in  the  development  of 
tubers  and  roots,  although  the  effects  were  observed  in 
all  parts  of  the  plant. 

The  Influence  of  Nitrogen.— Wilfarth'  showed 
that  when  the  supply  of  nitrogen  is  insufficient  the 
leaves  tend  to  turn  yellow,  and  that  if  the  available 
supply  of  potash  is  deficient  heavy  applications  of  nitro- 
gen tend  to  reduce  the  percentage  of  tubers  and  starch. 
L,awes  and  Gilbert3  show  that  nitrogen  stimulates  the 
production  of  starch,  provided  the  mineral  constituents 
are  not  deficient;  but  in  large  quantities  nitrogenous 
fertilizers  stimulated  luxuriant  growth,  delayed  matur- 
ation, and  produced  potatoes  richer  in  nitrogen  and 
much  more  liable  to  disease.  At  the  Rhode  Island 
Experiment  Station4  dried  blood  ranked  first  of  the 
nitrogenous  fertilizers  applied,  followed  by  nitrate  of 
soda  and  sulphate  of  ammonia;  but  on  soils  said  to  be 
extremely  acid,  dried  blood  was  only  about  half  as 


J  E.  S.  R.,  VII.,  p.  667.  »  E.  vS.  R.  XIV.,  p.  561. 

3  Rothamsted  Memoirs,  Vol.  VI.          *  R.  I.  Bui.  65,  pp.  133,  134. 


32  THE   POTATO 

beneficial  as  it  should  be;  hence,  such  soils  need  liming 
before  full  benefit  can  be  derived  from  the  use  of  this 
fertilizer.  A  mixture  of  two-thirds  dried  blood  and 
one-third  nitrate  of  soda,  or  of  equal  parts  of  all  three 
fertilizers,  is  suggested.  At  the  Tennessee  Experiment 
Station1  cottonseed-meal  was  found  to  be  a  more  profit- 
able source  of  nitrogen  than  nitrate  of  soda,  while  at 
the  Florida  Station3  the  nitrogen  of  cottonseed-meal 
and  castor  pomace  were  equally  effective,  but  that  of 
nitrate  of  soda  was  more  so  by  30  per  cent. 

The  Influence  of  Potash.— Wilfarth  and  Wim- 
mer3  show  that  when  potassic  fertilizers  are  applied  to 
a  soil  almost  destitute  in  potash  they — 

1 .  Increase  the  size  of  the  tuber,  but  have  little  influ- 

ence upon  its  composition,  and  that  the  amount 
of  potash  in  tubers  remains  fairly  constant,  unin- 
fluenced by  the  amounts  in  the  soil,  or  applied, 
unless  very  heavy  applications  are  made,  which 
may  cause  an  increase  to  a  certain  point,  but  will 
be  attended  by  a  decline  if  continued. 

2.  Decrease  the  percentage  of  stems  and  leaves,  but 

have  no  marked  influence  on  the  roots  of  potatoes. 

3.  Have  a  marked  influence  on  the  shape  and  appear- 

ance of  the  leaf;  if  deficient,  the  leaves  are  yellow- 
ish-brown in  color,  and  become  spotted  or  striped 
in  the  portions  between  the  veins,  while  the  peti- 
ole of  the  leaf  and  ribs  retain  their  dark  green 
color.  If  the  supply  of  potash  is  insufficient  the 
leaves  tend  to  curl,  and  sometimes  collapse  of  the 
plant  follows. 

i  Tenn.  Bui.,  Vol.  XIII.,  No.  3,  p.  6.  '  Fla.  Reiwrt,  1900-1901,  p  27 

*  E.  S.  R.,  XIV.,  p.  561. 


MANURING    AND   FERTILIZING  33 

4.  Increase  the  quantity  of  water  transpired  per  gram 
of  dry  matter. 

Hecke1  shows  that  the  application  of  potassic  fertil- 
izers has  a  marked  influence  in  the  production  of 
tubers  and  roots,  and  that  potash  assists  in  the  forma- 
tion of  starch.  Lawes  and  Gilbert2  noted  that  the 
percentage  of  potash  was  relatively  high  when  the 
supply  of  it  was  relatively  liberal  and  vice  versa,  but 
the  variations  are  small,  and  that  where  there  was  a 
deficiency  of  potash  in  the  supply  and  in  the  ash  there 
was  generally  an  increased  supply  of  lime  in  the  ash. 

Which  is  the  Better  Source  of  Potash,  Sul- 
phate or  Muriate  of  Potash  ? — This  question  is 
still  unsettled,  because,  apart  from  other  considerations, 
one  of  the  deciding  factors  is  the  relative  cost  of  each. 
In  many  cases  the  results  are  inconclusive,3  while  in 
some  cases4  the  fertilizers  appear  to  be  of  equal  value. 
In  others5  sulphate  of  potash  gave  better  results;  thus 
Davidson,  of  Virginia,*  found  that  the  potatoes  grown 
by  sulphate  of  potash  contained  more  dry  matter  but 
a  less  percentage  of  starch  than  those  fertilized  with 
muriate  of  potash.  Brooks'  found  that  sulphate  of 
potash  gave  a  greater  yield  per  acre  of  merchantable 
tubers,  which  were  of  larger  size  and  of  superior  eat- 
ing quality,  containing  2  to  3  per  cent,  more  starch, 
and,  when  cooked,  the  potatoes  were  whiter,  of  better 
flavor,  and  more  mealy. 


1  E.  S.  R.,  VII.,  p.  667.  *  Rothamsted  Memoirs,  Vol.  VI.,  "  Experi- 
ments on  the  Growth  of  Potatoes."  3  (N.Y.)  Geneva  Bui.  137,  pp.  604,  620. 
*  N.  H.  Bui.  41,  p.  13.  •  Mass.  (Hatch)  Report,  1896,  p.  22;  R.  I.  Bui.  65, 
p.  133  ;  Mich.  Bui.  131,  p.  10;  (N.  Y.)  Geneva,  Bui.  137,  pp.  621,  622.  •  Va.  Bui, 
92,  pp.  107,  108.  T  Mass.  (Hatch)  Report,  1904,  p.  122. 


34  THE  POTATO 

The  time  and  method  of  application  must  be  con- 
sidered. In  my  experience  muriate  of  potash  has  given 
better  results  when  applied  the  previous  fall,  especially 
if  more  than  100  pounds  per  acre  are  to  be  applied,  the 
presumption  being  that  the  potassium  compound  under- 
goes changes  in  the  soil,  and  that  the  injurious  chlorine 
i's  removed  as  a  chloride  by  the  winter  and  spring 
rains.  For  spring  application  in  the  drills  sulphate  of 
potash  may  be  better,  or  a  mixture  of  sulphate  and  mu- 
riate of  potash,  if  more  than  the  above-mentioned 
quantity  is  required.  The  disadvantage  of  the  muriate 
of  potash  seems  to  be  due  to  the  fact  that  it  is  a  chlo- 
ride, and  Sjollema1  and  Pfeiffer2  have  shown  that  the 
chlorides  of  potassium,  sodium  (common  salt) ,  and  mag- 
nesium, when  added  to  the  sulphate  of  potash,  dimin- 
ished the  starch  content  of  the  potatoes  considerably, 
and  that  the  reduction  was  greatest  in  varieties  rich 
in  starch.  This  would  seem  to  support  the  common 
idea  that  sulphate  of  potash  produces  better  quality 
potatoes  than  muriate  of  potash.  Wheeler,3  of  Rhode 
Island,  shows  that  calcium  chloride  had  a  marked 
poisonous  effect  upon  potatoes  and  nearly  destroyed 
them,  while  the  same  amount  of  calcium  in  certain 
forms  other  than  the  chloride  or  sulphate  increased  the 
yield  and  vigor  of  the  plants.  New  varieties,  and 
those  making  a  heavy  growth  of  haulm,  seem  to  be 
particularly  sensitive  to  chlorides. 

Influence  of  Phosphoric  Acid.— Lack  of  phos- 
phoric acid  is  accompanied  by  dark  green  leaves.  While 
phosphoric  acid  aids  starch  formation,  it  is  often  re- 


'  E.  S.  R.,  XII.,  434-     *  E.  S.  R.,  XII.,  443.     »  R.  I.  Bui.  40,  pp.  85,  86. 


MANURING   AND   FERTILIZING  35 

garded  as  being  of  less  importance  than  pot-ash.  The 
results  obtained  at  the  Ohio  Station '  show  that  phos- 
phoric acid  is  the  most  essential  fertilizer  for  their  con- 
ditions, some  potash,  and,  in  some  cases,  nitrogen,  being 
also  required.  I  found  the  same  to  be  true  at  Briar- 
cliff  Manor,  N.  Y.,  where  100  pounds  of  available 
phosphoric  acid  per  acre  (equal  to  600  pounds  acid 
phosphate,  16-17  per  cent,  available)  gave  profitable 
returns.  My  own  observations  are  that  an  excessive 
application  of  available  phosphoric  acid  has  a  marked 
influence  upon  the  foliage,  causing  it  to  be  small,  dark 
green,  wrinkled,  and  apparently  stunted  in  develop- 
ment, with  consequently  early  maturity.  In  some 
cases  the  period  of  growth  is  reduced  six  or  eight 
weeks,  and  consequently  the  yield  is  low;  but,  owing 
to  the  potatoes  being  mature,  the  quality  is  generally 
good.  In  certain  localities,  for  early  potatoes,  where 
it  is  desirable  to  hasten  maturity,  the  use  of  fair  quan- 
tities of  acid  phosphate,  with  a  limited  supply  of  nitro- 
gen and  potash  and  no  barn  manure,  is  found  to  be 
good  practice.  The  nitrogen  may  be  supplied  in  an 
available  form  as  nitrate  of  .soda,  since  nitrification 
may  not  be  active  in  the  soil  during  the  early  period 
of  growth. 

The  Influence  of  Calcium. — Calcium  does  not  ap- 
pear to  be  so  important  as  some  of  the  other  elements, 
although  in  some  cases  it  produces  a  marked  increase 
in  yield  (Fig.  10).  If  applied  in  a  form  which  has 
an  alkaline  action  upon  the  soil — as,  carbonate  of 
lime  or  quicklime — it  may  have  an  injurious  effect  by 


'Ohio  Bui.  125,  pp.  131,  132. 


36  THE   POTATO 

producing  conditions  which  aid   the   development  of 
scab. 

Barn  Manure. — Applying  barn  manures  is  com- 
monly practiced  for  potatoes  with  profitable  results. 
L,awes  and  Gilbert '  showed  that  only  a  small  portion 
of  the  nitrogen  of  farm  manures  is  taken  up  by  the  crop; 
thus,  with  an  annual  manuring  of  15.5  tons  per  acre, 
containing  200  pounds  of  nitrogen,  continued  for  twelve 


Courttsy  R.  I.  Exp.  Sta.     See  Bui.  40. 

FIG.  10 — INFLUENCE  OF  LIME  UPON  POTATOES 

Showing  the  influence  of  lime  upon  the  yield,  and  that  it  increases  the  per- 
centage of  scabbed  potatoes.    Right,  unlimed.    Left,  limed.    Other  fertil- 
izers the  same  in  both  cases. 

years,  but  8.3  per  cent,  of  the  nitrogen  was  recovered 
in  the  crop.  ' '  These  results  seem  to  indicate  that  this 
crop  is  able  to  avail  itself  of  a  less  proportion  of  the 
nitrogen  of  the  manure  than  any  other  farm  crop. 
Yet,  in  ordinary  practice,  farm-yard  manure  is  not  only 
largely  relied  upon  for  potatoes,  but  is  often  applied  in 
larger  quantities  for  them  than  for  any  other  crop." 
Taft,2  of  Michigan,  found  that  twenty-four  loads  of 
manure  per  acre  gave  the  largest  yield,  while  at  the 

1  Rothamsted  Memoirs,  Vol.  VI.      "  Mich.  Bui.  131,  p.  10. 


MANURING    AND    FERTILIZING  37 

Wisconsin  Experiment  Station  twenty  loads  per  acre 
were  applied,  and  larger  quantities  in  Great  Britau. 

It  seems  natural  to  assume  that  the  beneficial  effects 
of  manure  must  largely  be  due  to  other  causes  than 
the  addition  of  plant-food.  Among  these  may  be  its 
influence  on  the  physical  properties  of  the  soil,  render- 
ing it  more  retentive  of  moisture,  more  porous  and 
more  permeable  for  air  and  roots,  'and  a  better  home 
for  the  useful  soil  bacteria,  which,  in  fact,  it  may  sup- 
ply. The  decomposition  of  such  quantities  of  organic 
matter,  with  the  consequent  liberation  of  carbon  dioxid, 
aids  in  rendering  the  mineral  resources  of  the  soil  more 
available.  Generally  speaking,  it  is  more  economical 
to  apply  about  ten  tons  of  manure  per  acre  and  supple- 
ment it  with  fertilizers,  except  upon  loose  open  soils 
of  poor  texture,  where  the  beneficial  effect  from  the 
larger  amount  should  probably  be  ascribed  to  its  in- 
fluence upon  the  retention  of  moisture.  It  is  preferable 
that  the  manure  be  rotted  somewhat  and  applied  the 
previous  fall,  while  the  fertilizers  may  be  applied  when 
planting.  On  some  soils,  to  reduce  the  danger  of  dis- 
ease, it  may  be  advisable  to  apply  all  the  barn  manure 
to  the  previous  crop.  The  application  of  fertilizers  is 
profitable  under  most  conditions  in  the  Eastern  and 
North  Central  States.  At  New  Hampshire  Experi- 
ment Station  the  application  of  fifteen  cords  of  manure 
increased  the  yield  of  marketable  potatoes  over  100 
bushels  per  acre  compared  with  no  manure,  and  the 
use  of  i ,  500  pounds  of  fertilizers  with  the  same  amount 
of  manure  resulted  in  a  further  increase  in  yield  of 
130  bushels  per  acre.1  Taft,2  of  Michigan,  shows  that 

"  N.  H.  Bui.  in,  p.  116.      "  Mich.  Bui.  131,  p.  10. 

,'184982 


38  THE   POTATO 

the  average  gain  from  the  use  of  a  full  application 
of  fertilizers  was  eighty  bushels  per  acre.  In  Long 
Island,  N.  Y.,  a  fertilizer  mixture  containing  4  per 
cent,  nitrogen,  8  per  cent,  available  phosphoric  acid, 
and  10  per  cent,  potash  has  proven  satisfactory.  It 
is  used  in  amounts  varying  from  500  pounds  to  2,000 
pounds  per  acre,  and  in  many  cases  more  potash  is  ap- 
plied than  is  profitable.  The  use  of  i  ,000  pounds  of 
this  fertilizer  has  given  the  greatest  profit.  Where 
1,500  pounds  or  2,000 pounds  were  used  the  cost  of  the 
fertilizer  was  more  than  the  market  value  of  the  in- 
creased yield  of  potatoes.  For  some  years  I  have  used  a 
mixture  of  100  pounds  sulphate  of  ammonia,  400  to  600 
pounds  acid  phosphate  (16  to  17  per  cent,  available), 
and  loo  pounds  muriate  of  potash  with  eight  to  ten 
tons  of  partially  rotted  manure  per  acre  on  a  medium 
loam  soil.  At  New  Hampshire  Experiment  Station1 
300  pounds  muriate  of  potash  per  acre  gave  the  best 
results  when  compared  with  none,  150  pounds,  and  450 
pounds  per  acre. 

The  above  mixtures  merely  show  quantities  used  by 
certain  individuals  ;  each  farmer  must  work  out  a  mix- 
ture suited  to  his  needs.  There  are  other  conditions 
than  the  application  of  fertilizers.  As  Dr.  W.  H.  Jordan" 
pithily  puts  it:  "It  is  clearly  evident  that  a  large 
supply  of  plant-food  does  not  necessarily  insure  a 
satisfactory  crop.  Other  conditions  which  largely  per- 
tain to  culture — such  as  texture,  humus,  and  water- 
supply — exercise  a  controlling  influence,  and  when 
these  conditions  are  unfavorable  their  effect  is  not  over- 
come by  heavy  applications  of  fertilizer." 

1  N.  H.  Bui.  in,  p.  115.      »  (N.  Y.)  Geuera  Bui.  189,  p.  215. 


MANURING    AND    FERTILIZING  39 

It  almost  invariably  occurs  that  potatoes  grown  with- 
out any  manure  mature  earlier  and  contain  more  dry 
matter,  with  a  correspondingly  reduced  yield,1  than 
those  grown  on  land  manured  with  barn  manures  or 
a  complete  fertilizer.  The  vigorous  growth  induced 
under  the  latter  conditions  cannot  be  matured  in  the 
same  time,  hence  for  an  early  crop  it  is  unwise  to 
stimulate  too  vigorous  growth. 

The  Function  of  Fertilizers. — The  prevailing 
opinion  in  purchasing  fertilizers  is  that  they  contain 
a  certain  amount  of  plant-food — usually  nitrogen,  phos- 
phoric acid,  or  potash — in  a  more  or  less  available 
form,  and  that  the  benefits  received  from  their  appli- 
cation is  due  to  the  addition  of  this  plant-food  to  the 
soil.  So  deeply  seated  is  this  theory  that  all  fertilizers 
are  bought  and  sold  on  this  basis,  and  laws  controlling 
the  business  have  been  formulated  upon  it.  The  in- 
gredients— nitrogen,  phosphoric  acid,  and  potash,  with 
others — are  necessary  for  the  growth  of  all  crops,  but 
the  amounts  of  the  essential  ingredients,  other  than 
the  above  mentioned,  are  believed  to  be  present  in  the 
soil  in  sufficient  quantities  to  meet  all  the  requirements 
of  the  crops  grown. 

A  3oo-bushel  crop  of  potatoes  has  been  found  to  con- 
tain 8 1  pounds  of  nitrogen,  30.6  pounds  of  phosphoric 
acid,  and  79  pounds  of  potash.  Taking  49  New  York 
soils,  the  chemist  found  that  the  surface  eight  inches 
contained,  per  acre  :  * 

Nitrogen    .     .     .     3,053  pounds,  enough  for    38  crops 
Phosphoric    acid,    4,219         "  "         "    137     " 

Potash  ....    16,317         "  "         "    207     " 


Va.  Bui.  92,  p.  107.  »  (N.  Y.)  Cornell  Bui.  130,  p.  157. 


40  THE   POTATO 

Upon  such  soils  as  these  applications  of  fertilizers 
containing  phosphoric  acid,  and,  in  some  cases,  potash, 
have  been  found,  by  experience,  to  be  most  profitable — 
a  condition  of  affairs  which  could  never  be  ascertained 
from  the  analyses.  It  is  seldom  that  the  increase  in 
yield  of  crop  bears  any  relationship  to  the  quantity  of 
the  fertilizers  applied.  Without  either  fertilizers  or 
manure,  but  given  good  tillage,  yields  of  300  bushels 
of  potatoes  per  acre  have  been  obtained  for  four  suc- 
cessive years  on  the  same  piece  of  land.1 

The  amount  of  plant-food  removed  by  any  crop  is 
small,  and  is  obtained  from  all  parts  of  the  soil  wherever 
roots  extend.  Most  soils  contain  certain  sufficient  plant- 
food  to  supply  the  demands  of  any  crop  grown  thereon 
for  an  indefinite  period  of  time.  To  maintain  crop  pro- 
duction at  a  profitable  point,  attention  must  be  paid 
to  factors  other  than  the  supply  of  plant-food. 

The  ingredients  applied  as  fertilizers  will,  no  doubt, 
be  found  to  have  a  value  other  than  their  value  as  car- 
riers of  plant- food.  Their  value  for  this  purpose  may 
be  found  to  be  small,  while  the  benefits  derived  from 
their  use  may  be  found  to  be  largely  due  to  their 
chemical  adlion  upon  the  soil — e.g.,  as  sanitary  agents, 
promoters  of  the  growth  of  desirable  organisms  or  de- 
stroyers of  injurious  ones,  aids  in  the  formation  of  de- 
sirable chemical  compounds  in  the  soil  or  neutralizers 
of  undesirable  compounds,  to  their  influence  as  stimu- 
lants, and  upon  the  physical  properties  of  the  soil. 
That  their  use  is  desirable  in  some  cases  is  evident. 
Why  it  should  be,  and  how,  are  matters  for  investiga- 
tion. 

1  (N.  Y.)  Cornell  Bui.  191,  p.  192. 


MANURING   AND    FERTILIZING  41 

The  farmer  needs  to  realize  that  the  soil  on  his  fields 
to-day  is  not  the  same  as  that  of  last  year.  Soil  is 
changing.  The  subsoil  of  yesterday  is  the  soil  of 
to-day.  Although  the  amount  removed  by  crops  is  so 
small  that  it  is  a  negligable  quantity,  that  removed  by 
washing  and  by  the  wind  is  enormous.  The  muddy 
stream,  the  bars  at  the  mouths  of  rivers,  the  move- 
ment of  soils  by  the  wind,  and  even  the  dust-cloud 
raised  when  harrowing,  show  that  far  more  plant-food 
is  removed  in  these  ways  than  in  crops,  and  to  check 
these  leaks  is  of  more  importance  than  to  try  to  make 
up  the  loss  by  the  addition  of  plant-food.  The  main- 
tenance of  a  satisfactory  amount  of  organic  matter  in 
the  soil  in  a  proper  condition  may  usually  be  accom- 
plished by  a  judicious  rotation  of  crops,  manuring,  and 
liming. 

' '  The  old  method  has  been  to  feed  crops  with  com- 
mercial fertilizers,  the  new  agriculture  looks  to  nature 
for  its  sources  of  plant-food.  These  sources  are  (i) 
the  large  stores  of  unavailable  plant-food  in  all  soils, 
(2)  the  unlimited  stores  of  nitrogen  present  in  the 
air."1  Research  has  revealed  the  fact  that  soil  or- 
ganisms can  take  plant-food  from  both  of  the  above 
sources  and  furnish  it  to  growing  crops,  and  that  a 
fertile  .soil  is  one  in  which  these  processes  are  going  on 
at  the  highest  rate,  and  that  it  is  necessary  to  stimu- 
late these  biological  activities.  Humus  is  a  food  for 
these  organisms.  L,ime  is  essential  for  maintaining  the 
soil  in  a  slightly  alkaline  condition,  and  for  fixing 
some  of  the  compounds  formed  in  the  soil;  and  drain- 


Dei.  Bui  66,  p.  14. 


42  THE   POTATO 

age,  deep  plowing,  and  thorough  tillage  are  necessary 
to  bring  air  into  the  soil  and  stimulate  bacterial  activ- 
ity. Humus,  lime,  and  tillage  are  three  important  fac- 
tors in  maintaining  a  fertile  soil/  and  the  farmer  who 
understands  the  value  of  these  is  the  one  who  will  de- 
rive the  most  benefit  from  the  use  of  fertilizers. 

Purchasing  and   Applying  Fertilizers. — Fertil- 
izers may  be  divided  into  three  classes — viz. : 

(a)  Nitrogenous,  or  those  rich  in  nitrogen. 

(6)   Phosphatic,  or  those  rich  in  phosphorus. 

(r)    Potassic,  or  those  rich  in  potassium. 
Nitrogen  occurs  in  fertilizers,  as  : 

(1)  Nitrates — e.g.,    nitrate   of    soda,     nitrate    of 

potash. 

(2)  Ammonium    salts  —  e.g.,  sulphate    of    am- 

monia. 

(3)  Organic  nitrogen — e.g.,  dried  blood,  tankage, 

hoof  meal,  etc. 

Nitrogen  as  nitrates  is  immediately  available 
as  plant- food,  is  soluble  in  water,  and  if 
not  taken  up  quickly  by  plants  is  liable 
to  be  lost  in  the  soil  water;  hence  small 
quantities  applied  at  short  intervals  give  the 
best  results. 

Nitrogen  as  ammonium  salts  soon  becomes 
available  in  warm  weather,  and  is  not  so 
liable  to  be  washed  out  of  the  soil  as  when  in 
the  form  of  a  nitrate. 

Nitrogen  as  organic  matter  is  more  slowly 
available. 


1  Del.  Bui.  66,  "  Soil  Bacteria  and  Nitrogen  A^similatiot 


MANURING   AND   FERTILIZING  43 

Phosphorus  occurs  in  fertilizers,  as  : 

1 i )  Insoluble  phosphate  of  lime — e.g. ,  floats,  bone 

meal,  tankage. 

(2)  Soluble  phosphate  of  lime — e.g.,   acid  phos- 

phate, dissolved  bone. 

Insoluble  phosphate  of  lime  is  considered  to 
be  but  slowly  available.  It  is  converted 
into  "  soluble  "  by  treating  it  with  an  acid, 
usually  sulphuric  acid. 

Soluble  phosphate  of  lime,  as  a  rule,  is  more 
active  than  insoluble  in  promoting  plant 
growth,  but  on  acid  soils  insoluble  phos- 
phate often  gives  better  returns.  The 
soluble  phosphate  of  lime  and  a  phosphate 
soluble  in  weak  acids  constitute  the  ' '  avail- 
able phosphoric  acid  ' '  of  the  chemist. 
Potassium  is  the  valuable  ingredient  found  in  : 

Wood  ashes,  kainit,  sulphate  of  potash,  double 

salts,  and  muriate  of  potash. 
It  usually  gives  good  returns  when  applied  to 
light,  sandy,  and  peaty  soils.      As  kainit 
contains  chlorides  and  muriate  of  potash  is 
a  chloride,  it  is  often  advisable  to  apply 
them  some  time  previous  to   planting  the 
crop,  in  order  that  the  injurious  substances 
may  be  removed  by  the  soil  water,  chlorides, 
in  excess,  being  injurious  to  potatoes. 
Value. — All  fertilizers  may  be  valued  according  to 
the  percentage  of  nitrogen,  soluble  phosphate  of  lime, 
insoluble  phosphate  of  lime,  and  potash  present.    They 
are  often  valued  on  the  unit  system.     A  unit  is  one  per 
cent,  of  a  ton,  or  20  pounds;  the  ton,  2,000  pounds. 


44  THE  POTATO 

Unit  Value. — In  order  to  find  the  unit  value  of  the 
different  ingredients,  divide  the  price  per  ton  of  the 
fertilizer  by  the  percentage,  or  number,  of  units  of  the 
various  valuable  ingredients;  this  will  give  the  cost  per 
unit.  For  example,  if  sulphate  of  ammonia  be  $66.00 
per  ton  and  contains  20  per  cent,  of  nitrogen,  then 
66  -«-  20  =  3.30  per  unit  (see  Table,  p.  45). 

If  the  price  per  pound  be  desired,  divide  the  price 
per  unit  by  20,  or  the  number  of  pounds  in  the  unit; 
thus,  3.30  •*-  20  =  16.5  cents  per  pound. 

For  a  fertilizer  containing  several  ingredients,  find 
the  lowest  cost  of  each  ingredient  in  a  standard  fertil- 
izer— as,  nitrate  of  soda  for  nitrogen,  muriate  of  potash 
for  potash,  and  acid  phosphate  for  soluble  phosphoric 
acid — and  compare  it  with  these. 

Purchasing  Fertilizers. — In  purchasing  fertilizers 
it  is  advisable  to  write  for  quotations  with  guaranteed 
analyses,  ascertain,  as  indicated  above,  the  cheapest 
source  of  the  valuable  ingredients,  and  then  purchase. 

The  fertilizer  containing  a  unit  of  plant-food  at  the 
lowest  cost  is  generally  the  one  to  buy.  In  figuring 
the  cost  always  include  the  freight,  cost  of  hauling, 
and  handling;  for  instance,  one  ton  of  muriate  of  pot- 
ash contains  as  much  potash  as  four  tons  of  kainit, 
hence  the  potash  as  muriate  of  potash  costs  only  one- 
quarter  as  much  for  haulage  and  handling.  The  same 
applies  to  high  grade  acid  phosphate  and  low  grade, 
and  unless  the  filler  is  of  some  particular  value  it  is 
wise  to  take  the  high  grade  or  concentrated  goods. 

Barn  Manure.— When  not  applied  to  the  fields 
as  soon  as  made,  it  should  be  stored  under  cover  and 
the  excrete  from  the  various  farm  animals  mixed, 


MANURING   AND   FERTILIZING 
TABLE    III 


SHOWING  THE    COST    OF    THE    DIFFERENT    INGREDIENTS   IN 
CERTAIN  FERTILIZERS  DURING  1904 


VALUABLE   INGREDIENTS 

COST 

NAME  OK  FERTILIZER 

£"« 

1? 

||| 

I- 

«'§> 

"S-5'^ 

is  £ 

Is  -a 

Per 

Per 

Per 

I! 

8^1 

5^4 

is 

Ton 

Unit 

Lb. 

1^ 

«•«! 

^1 

c 

t 

$ 

Cts. 

Nitrate  of  Soda  .... 

15-5 

44.00 

2.84 

14.2 

.Sulphate  of  Ammonia  . 
Dried  Blood  (high 

20 

66.00 

3-30 

16.5 

grade)  
Dried  Blood  

13 

II 

45-00 
3H.oo 

3.46 

3-  38 

17-3 
16.9 

28.00 

14.2 

Fresh  Bone  Meal  .   .  -j 
( 

1.25 

22 

2'86 

3-8 
14.2 

Steamed  Bone  Meal  .  < 

26.00 

• 

28 

.80 

4  o 

Fine  Ground  Bone      j 

5 

2.84 

14.2 

Tankage  j 

'4 

27.00 

.91 

4-5 

Fine    Ground   Bone      t 

7 

34.00 

2.84 

14.2 

Tankage  j 

9 

1.57 

78 

Acid   Phosphate  .... 

13 

II.OO 

.85 

4.2 

Acid  Phosphate  .... 

16 

40 

15  oo 
40.00 

•94 

I.OO 

47 
5-o 

Acid  Phosphate  .... 

Kainit  

12 

12.00 

I.OO 

5.0 

Double  Salts  of  Potash 

and  Magnesia  .... 
Sulphate  of  Potash.  .   . 
Muriate  of  Potash  .   .   . 

26 

48 

26.0O 
48.00 
43.00 

I  OO 

I  00 

.86 

5-o 
50 
4-3 

Analysis  of  a  ton  of  ( 
well-made  Barn  Ma--? 

•45 

•54 

1.  10 

1.42 
•38 

7-1 
'•9 

nure  ( 

.61 

•43 

2.1 

Another  sample  of      j 
Manure                        ") 

'•63 

.14 

'    '.67' 

1.24 

•43 

1-9 

2.1 

when  the  cold  cow  and  pig  manure  will  tend  to  pre- 
vent excessive  loss,  by  heating,  from  the  horse  ma- 
nure. Young  growing  animals  and  those  bearing 
young  and  giving  milk  will  give  poorer  excrete  than 


46  THE   POTATO 

mature  fattening  animals.     The  food  and  the  litter 
used  also  affect  the  value  of  the  manure. 

In  barn  manure  the  nitrogen,  phosphoric  acid  and 
potash  are  slowly  available,  and  are  arbitrarily  reck- 
oned to  be  worth  half  what  they  would  cost  in  fer- 
tilizers. The  value  of  a  ton  of  manure  for  its  physical 
effect  upon  soils  cannot  be  expressed  in  dollars  and 
cents,  but  in  the  Eastern  States  it  may  be  presumed  to 
vary  between  50  cents  and  $1.00  per  ton;  for  while  the 
fertilizing  ingredients  show  a  value  of  about  $1.25, 
the  manure  often  costs,  or  is  valued  at,  $2.00  per  ton. 

Mixing  Fertilizers.— Fertilizer  manufacturers  lay 
great  emphasis  on  the  value  of  proper  mixing,  and 
usually  charge  from  $5  to  $10  per  ton  for  doing  it. 
For  example,  a  commercial  potato  manure  analyzing 
nitrogen,  3  percent.,  phosphoric  acid,  6  per  cent.,  and 
potash,  10  per  cent,  costs  in  New  Hampshire',  in  1904, 
$36.50  per  ton.  A  fertilizer  made  up  by  the  station 
on  the  same  formula  was  just  as  satisfactory,  and 
after  allowing  $1.00  per  ton  for  mixing,  it  cost  $24 
per  ton,  a  saving  of  $8.50  per  ton,  or  using  1,500 
pounds  per  acre  =  $7.10  per  acre. 

To  compound  this  fertilizer: 
3  per  cent,  nitrogen  =  60  pounds  nitrogen  in  a  ton 

(2,000  pounds). 
6  per  cent,  phosphoric  acid  =  120  pounds  phosphoric 

acid  in  a  ton. 
10  per  cent,  potash  =  200  pounds  potash  in  a  ton. 

Nitrate  of  soda  will  furnish  nitrogen  for  immediate 
use,  and  the  nitrogen  of  the  sulphate  of  ammonia  will 


MANURING  AND    FERTILIZING  47 

become  available  later  on,  hence  we  may  take  23^ 
pounds  nitrogen  in  the  form  of  nitrate  of  soda,  and 
36^  pounds  in  the  form  of  sulphate  of  ammonia. 
Cottonseed-meal,  dried  blood,  tankage,  etc.,  might 
also  be  used  if  desired. 


Nitrate  of  soda  containing  15^  per  cent,  nitrogen ;  to  fur- 
nish 23l/4  pounds  nitrogen  it  requires  150  pounds  .  150 

Sulphate  of  ammonia  containing  20  per  cent,  nitrogen; 
to  furnish  36%  pounds  nitrogen,  it  requires  184 
pounds 184 

Acid  phosphate  containing  16  per  cent,  available  phos- 
phoric acid;  to  furnish  120  pounds  phosphoric  acid  it 
requires  750  pounds 750 

Muriate  of  Potash  containing  50  per  cent,  potash;  to 

furnish  200  pounds  potash  it  requires  400  pounds  .  400 

Filling,  sand,  etc.,  used  to  make  weight  if  desired     .     .       516 


Unless  care  be  taken  in  mixing  fertilizers  loss  of 
valuable  ingredients  may  result. 

1 .  Nitrate  of  soda  and  soluble  phosphate  of  lime — as, 

acid  phosphate — must  not  be  mixed  and  allowed 
to  stand  for  any  length  of  time,  or  chemical  action 
will  take  place,  resulting  in  a  loss  of  nitrogen  and 
phosphoric  acid. 

2.  Do  not  mix  an  ammonium  salt — as,  sulphate  of  am- 

monia— with  any  other  fertilizer  containing  free 
lime,  as  the  lime  will  set  free  the  ammonia,  which 
will  be  lost. 

3.  Do  not  mix  soluble  and  insoluble  phosphates  to- 

gether. 


48  THE  POTATO 

4.  Nitrate  of  soda  is  very  deliquescent,  and   if  left 

mixed  with  other  fertilizers  is  liable  to  render  the 
whole  mass  wet  and  pasty,  and  so  difficult  to 
apply.  Cottonseed-meal  is  a  very  useful  source 
for  part  of  the  nitrogen  of  mixtures.  If  it  is  nec- 
essary to  hold  a  quantity  of  nitrate  of  soda  for  a 
time,  it  is  advisable  to  empty  it  out  of  the  bags, 
as  they  are  liable  to  ignite  spontaneously.  When 
emptied  do  not  leave  the  bags  lying  in  a  heap  in 
the  corner  of  the  barn.  Store  nitrate  of  soda  in  a 
dry  place. 

5.  Kainit  is  also  very  deliquescent,  and  it  is  the  worst 

potassic  fertilizer  to  use  in  a  mixture  on  this  ac- 
count. Sulphate  or  muriate  of  potash  are  better 
for  mixtures. 

Applying  Fertilizers.  —  When  a  horse  planter  is 
used  the  fertilizer  is  usually  distributed  in  the  row  at 
the  time  of  planting.  The  fertilizer  may  be  sown 
broadcast  or  in  the  rows  as  desired,  but  it  should  be 
incorporated  with  the  soil  and  not  left  on  top. 

Water  Requirement.  —  It  has  been  shown  clearly 
that  the  available  water  content  of  the  soil  exerts  a 
great  influence  upon  the  life  of  the  potato  plant,  upon 
its  assimilation  of  plant-food,  and  upon  the  yield.  At 
the  Wisconsin  Experiment  Station  '  it  was  found  that 
when  two  acre  inches  of  water  were  added  in  two  irri- 
gations in  one  case  the  yield  was  increased  100  bushels 
of  salable  potatoes  per  acre,  thus  showing  that  the 
right  amount  of  water  at  the  right  time  is  a  very  im- 
portant factor  in  determining  the  yield.  Whitson,*  of 


i  \Vis.  Report,  it*/,,  p.  214.  2  Wis.  Report,  1902,  p.  190. 


MANURING   AND   FERTILIZING  49 

Wisconsin,  shows  that  if  it  is  assumed  that  under  the 
existing  climatic  conditions  of  that  State  1 8  inches  of 
rainfall  during  the  growing  season  is  sufficient  for  po- 
tatoes, then,  on  this  basis,  there  was  a  shortage  of  4 
inches  or  more  in  ten  of  the  past  twenty-one  years.  In 
Utah 1  it  was  noted  that  the  largest  yield  was  obtained 
from  a  plat  irrigated  every  eighth  day  and  receiving  14 
inches  of  water,  and  another  year8 16.62  inches  of  water 
with  praclically  no  rain  produced  a  yield  of  423  bushels 
per  acre.  The  importance  of  water  was  also  shown  at 
the  same  station,3  when  amounts  of  water  varying  be- 
tween 4.3  inches  and  9.45  inches  were  applied  between 
July  1 8  and  August  6,  and  the  yield  increased  with 
the  increase  in  amount  of  water.  At  the  New  Jersey 
Station4  irrigation  increased  the  yield  36.4  per  cent., 
while  at  Wisconsin  the  increase  has  been  159.58  6  bush- 
els per  acre  over  the  unirrigated  plat,  and  the  average 
gain  per  year  during  the  six  years — 1896-1901 — was 
83.9  bushels  per  acre.  That  some  risk  must  be  taken 
in  irrigating  heavy  soils  in  a  humid  climate  was 
demonstrated  at  Wisconsin.8  Thus,  in  one  year, 
while  there  was  an  increase  of  81.4  bushels  per  acre 
from  irrigating  sandy  land,  on  heavier  land  the  yield 
was  reduced  56  bushels  per  acre  because  heavy  rain 
followed  the  second  irrigation. 

Corn  and  potatoes  require  somewhat  similar  amounts 
of  water  to  make  one  pound  of  dry  matter.  The  figures 
of  Wilfarth  and  Wimmer 7  and  Whitson8  are  as  follows: 


Utah  Report,  1893,  p.  180.  a  Utah  Bui.  26,  p.  14. 

Utah  Bui.  5.  *  N.  J.  Report,  1900,  p.  184. 

Wis.  Report,  1901,  p.  198.  •  Wis.  Report,  1900,  p.  188. 

E.  S.  R.,  XIV.,  p.  561.  •  Wis.  Report,  1902,  p.  191. 


50  THK  POTATO 


WATER   USED  PER    POUND  OK  DRY  MATTER 


WILFARTH   AND   WIMMER 


WHITSON 


Pounds 

Corn 270 

Soy-beans 527 

Clover 576 

Oats 503 


Pounds 

Potatoes      .     .     .     200  to  230 
Tobacco       .     .     .     300  to  370 

Buckwheat 400 

Chicory 400 

Mustard 500 

Oats 46° 

King '  has  shown  that  the  amount  of  water  required 
to  make  one  pound  of  dry  matter  in  the  tuber  and  vine 
of  potatoes  varied  between  272  pounds  and  497  pounds 
during  the  years  1892-7,  while  that  for  oats  ranged  oe- 
tween  446  and  595  pounds;  barley,  375  to  404  pounds; 
peas,  477;  corn,  223  to  398  pounds;  clover  (first  crop), 
370  to  582  pounds;  clover  (second  crop),  730  to  983 
pounds. 


"Irrigation  and  Drainage."    F.  H.  King. 


y 


CHAPTER  VI 
CONSIDERATIONS  OF   SEED 

Source  of  Seed. — It  is  often  advised  that  potatoes 
be  obtained  from  another  soil  and  from  a  more  north- 
ern latitude  if  vigor  and  delayed  maturity  are  desired, 
and  from  a  southern  latitude  if  earliness  is  sought; 
but,  generally  speaking,  potatoes  bred  for  a  district  do 
better  there  than  elsewhere.  Few  European  varieties 
of  potatoes  are  worth  growing  in  America,  and  any  in- 
troduction requires  acclimatization  and  selection.  In 
England  we  noted  that  northern  grown  Scotch  seed 
did  not  yield  so  heavily  the  first  year  as  the  second, 
and  the  same  was  true  of  Maine  grown  seed  in  the 
Hudson  River  valley.  Brooks,1  of  Massachusetts, 
and  Bishop,  of  Maryland,  report  exactly  to  the  con- 
trary, although  in  a  subsequent  year  Brinkley,3  at  the 
same  station,  obtained  higher  yields  from  home  grown 
seed.  The  Rhode  Island  Station3  found  that  varieties 
which  produced  large  yields  gave  increasing  yields  the 
longer  the  seed  tubers  had  been  home  grown,  and  that 
those  which  produced  smaller  yields  gave  diminishing 
yields  the  longer  the  seed  had  been  home  grown.  At 
Louisiana  Station4  home  grown  seed  was  equal  to,  if 
not  better,  than  western,  or  eastern  grown  or  Boston 
seed.  At  Georgia  Station5  southern  grown  seed  did 


i  Mass.  (Hatch)  Report,  1896,  pp.  25,  26.      a  Md.  Bui.  17,  p.  257. 

8  R.  I.  Report,  1897,  p.  380.  *  I,a.  Sacond  Series  Bui.  4,  p.  77. 

6  Ga.  Bui.  17,  p.  166. 


tj2  THE   POTATO 

best,  and  the  statement  is  made  that  the  value  of  seed 
depends  more  upon  the  care  exercised  in  the  selection 
of  the  strain  than  the  locality  where  it  is  grown. 
Martinet1 ,  of  France,  reports  that  in  several  diversified 
trials  seed  tubers  from  higher  altitudes  gave  better 
yields  under  all  circumstances. 

Bailey3,  of  Cornell,  lodges  a  criticism  against  the 
comparison  of  northern  and  southern  grown  seed.  He 
believes  the  variations  to  be  due  much  more  to  the 
stock  itself — how  the  plants  have  been  grown  and 
handled  in  previous  years — than  to  any  influence  of 
latitude.  He  believes  it  to  be  impossible  to  secure 
stock  from  different  growers  which  is  sufficiently  uni- 
form to  allow  of  comparative  experimentation.  That 
such  variation  exists  is  shown  by  Brooks'3  observation 
on  Beauty  of  Hebron  and  Early  Rose  potatoes.  Seed 
potatoes  of  the  same  variety  obtained  from  different 
localities  gave  a  variation  in  yield  of  about  50  per  cent, 
for  each  variety.  Probably  the  matter  is  one  of  indi- 
viduality. It  is  necessary  to  study  each  potato  and 
hill,  and  perpetuate  a  variety  suited  to  the  particular 
environment.  If  this  variety  possesses  the  capacity  of 
adapting  itself  rapidly  to  other  environments  it  is  more 
useful,  but  it  must  be  able  to  grow  vigorously  and 
mature  its  tubers  in  order  to  maintain  its  value.  The 
Ohio  Experiment  Station4  found  that  the  selection  and 
storage  of  potatoes  is  of  more  importance  than  the  use 
of  seed  grown  on  other  soil.  Kansas  Experiment  Sta- 
tion6 found  that  tubers  matured  in  July  were  the  most 

1  E.  S.  R.,  XII.,  p.  636.  "  (N.  Y.)  Cornell  Bui.  25,  p.  175. 

3  Mass.  (Hatch)  Report  1899,  P-  82  *  Ohio  Bui.  76,  p.  46. 

•  Kans.  Bui.  37,  pp.  155,  136. 


CONSIDERATIONS  OF    SEED  53 

satisfactory  seed  for  the  second  crop,  and  the  practice 
of  using  first-crop  tubers  as  seed  for  the  second  crop 
is  rapidly  gaining  ground  in  the  South,  owing  to  the 
difficulty  of  holding  seed  over. 

Management  of  Potatoes  Previous  to  Plant- 
ing.— The  best  way  to  hold  seed  potatoes  is  in  cold 
storage  at  a  temperature  of  33°  to  35°  F.  Should  the 
temperature  fall  to  freezing-point  (32°  F.)  for  a  short 


FIG.   II — A   USEFUL   POTATO   TRAY    FOR    THE   STORAGE   AND 

SPROUTING    OK    SEED    POTATOES 

For  small  quantities,  a  useful  size  is  24  x  1 2  inches.    This  size  will  hold 

about  forty  pounds  of  tubers,  and  can  be  conveniently  handled.    The 

larger  size  holds  about  eighty  pounds  of  tubers. 

time  probably  no  harm  will  result,  as  the  freezing- 
point  of  potatoes  is  rather  lower  than  that  of  water. 
As  most  farmers  do  not  have  cold  storage  some  sub- 
stitute must  be  found.  A  cool,  fairly  dry  cellar,  or  a 
root-house,  is  a  very  good  alternative,  or,  failing  this, 
the  potatoes  may  be  pitted  outside  and  covered  so  that 
no  frost  can  reach  them  (see  "Storing").  Several 
weeks  before  planting  the  tubers  should  be  spread  out 
on  the  barn  floor  two  or  three  thick,  in  the  light,  to 
quicken  growth.  Potatoes  vary  in  the  time  they  take 


54  THE   POTATO 

to  germinate.  Mature  potatoes  will  not  begin  to  grow 
until  they  have  had  a  period  of  rest.  In  some  varie- 
ties this  may  be  but  a  few  weeks,  while  others  may 
be  held  months  before  they  show  signs  of  growth. 
In  the  island  of  Jersey  and  the  early  potato  grow- 
ing districts  of  the  United  Kingdom  it  is  customary 
to  store  the  seed  potatoes  in  flat  trays  (Fig.  n). 
The  advantages  of  these  are:  (i)  the  seed  cannot  heat; 
(2)  a  large  quantity  can  be  stored  in  a  room,  the  trays 
being  tiered  almost  to  the  roof;  (3)  seed  can  be  easily 
examined  at  any  time  and  conveniently  moved,  hence 
diseases — as,  wet-rot,  dry-rot,  etc. — are  more  easily  con- 
trolled; (4)  the  potatoes  may  be  sprouted  in  the  trays; 
(5)  the  potatoes  can  be  moved  to  the  field  in  and 
planted  from  the  trays. 

The  tray  is  the  best  means  of  storing  new  varieties 
which  have  been  purchased  or  grown  in  small  quan- 
tities. 

Sprouting  Potatoes. — Lavallee1  and  many  others 
have  found  that  sprouting  seed  potatoes  in  a  well- 
lighted  room  increases  the  yield  and  earliness,  and 
produces  a  more  vigorous  growth  of  vines  and  a  larger 
starch  content  in  the  tubers.  One  explanation  offered 
for  the  increase  in  yield  is  that  the  short,  thick  stem 
developed  under  the  above  conditions  bears  many 
scales  or  leaves  for  its  hight,  and  it  is  from  the  axils 
of  these  scales,  the  place  where  the  scale  joins  the 
stem,  that  the  tuber-bearing  branches  are  produced 
(Fig.  12).  The  more  scales  produced,  the  more  op- 
portunity for  the  development  of  tubers.  If  the  tu- 
bers start  growth  in  the  dark,  either  indoors  or  below 

1  K.  S.  R.,  XII.,  p.  1032. 


CONSIDERATIONS   OF    SEED 


55 


ground,  the  scales  are  formed  at  longer  intervals,  and 
there  are  correspondingly  fewer  places  for  the  produc- 
tion of  tuber-bearing  branches.  Also,  in  the  latter 


Drawing 


FIG.    12 — POTATO    PLANTED    FOUR    INCHES    DEEP 

(Diagra  m  m  atic) 

a— Ground  level,  b — Seed  potato,  c — Short  sprout  sent  up  before  plant- 
ing, which  sent  up  two  branches,  d,  e ;  d  being  broken  off,  and  e  cut  off  at/. 
g—  The  tuber-bearing  stem,  or  rhizome,  which  bears  buds  at  h,  and  thickens 
at  the  end  to  form  a  tuber,  *',  upon  which  eyes  having  buds,  k,  maybe  seen. 
m  is  a  tuber-bearing  branch,  or  rhizome,  which  has  not  yet  begun  to  form 
a  tuber,  and  r  shows  where  the  roots  were  broken  off.  Generally  four  roots 
are  sent  out  for  each  tuber-bearing  branch. 

case,  the  leaf-bearing  branches  produced  above  ground 
are  weaker.  The  system  is  considered  essential  in 
the  island  of  Jersey  and  the  early  potato  growing  dis- 
tricts of  the  United  Kingdom,  and  is  practiced  to  a 
small  extent  for  the  second  crop  in  the  Southern  States. 


Ftgs.  13,  14,  15,  courtesy  Cornell  Unir.  Dept.  of  Horticulture. 
FIG.   13 — POTATOES  SPROUTED  PROPER    LENGTH    FOR    THE  PLANTER 
Starting  the  growth  of  the  tubers  in  this  way  is  profitable  in  many  places. 


F-IO.   14 — EARLY   POTATOES    SPROUTED   FOR   HAND    PLANTING 
Linger  sprouts  than  these  should  not  be  permitted  to  deve  lop. 


CONSIDERATIONS   OF    SEED  57 

By  sprouting  the  seed  tubers,  the  Kansas  Experiment 
Station1  have  planted  potatoes  in  March  and  lifted  the 
crop  on  June  i .  At  the  Rhode  Island  Experiment  Sta- 
tion2 potatoes  were  held  in  a  fairly  well-lighted  room 
at  a  temperature  of  60°  to  75°  F.  for  four  to  six  weeks. 


FIG.   15 — SPROUTS   TOO    LONG   AND   WEAK 

This  often  occurs  when  potatoes  are  left  in  sacks,  barrels,  or  in  piles  in  the 

cellar.    As  soon  as  sprouting  begins,  spread  the  tubers  thinly  on  the  barn 

floor,  in  the  light,  to  check  this  waste  of  energy. 

In  this  time  thick  buds,  one-half  to  an  inch  long  and 
one-quarter  to  three-eighths  of  an  inch  in  diameter, 
formed  (Fig.  14).  The  potatoes  may  be  held  at  this 
stage  for  some  weeks  if  necessary  by  lowering  the  tem- 
perature. Early  Rose  potatoes  weighing  about  three 
ounces  each  were  sprouted  as  described,  and  planted  on 
May  i  beside  similar  tubers  which  were  unsprouted. 


Kan.  Bui.  70,  p.  149,  and  Press  Bui.,  March  6,  1899. 
R.  1.  Bui.  36,  pp.  9-19. 


THE  POTATO 


Part  of  the  crop  was  harvested  July  29,  the  yield  being 
decidedly  in  favor  of  the  sprouted  seed,  which  lead  was 
maintained  (see  Table). 

TABLE  IV 

YIE1.D  PKR  ACRE  FROM  SEED  TUBERS  SPROUTED  AND  NOT 
SPROUTED 


Date. 
Harvested 

YIELD  PER  ACRE 

Total 

Gain  bv 
Sprouting 

Increase 
from 
Further 
Growth 

Large        Small 
Tubers        Tubers 

Sprouted  
Not  sprouted.. 

July  29... 
July  29... 

Bushels  Bushels 
97.96        53-23 
76.10       42.78 

Bushels 

Bushels 
32-31 

Bushels 

Sprouted  
Not  sprouted  .  . 

Aug.  20.. 
Aug.  20.  . 

135-47        55-51 
94-45        41-9° 

190.98 
I36-35 

54-63 

33-79 
'7-47 

In  trials  made  at  Cornell  Station  by  the  writer  dur- 
ing 1904,  with  the  varieties  Sir  Walter  Raleigh  and 
Carman  No.  3,  increased  yields  of  from  0.9  per  cent, 
to  73.7  per  cent,  resulted  from  sprouting  potatoes  in 
the  light  for  36  days  previous  to  planting,  when  com- 
pared with  holding  them  in  a  root-cellar  to  the  time  of 
planting.  The  sprouts  on  the  tubers  held  in  the  cellar 
were  up  to  three  inches  long;  those  held  in  the  light 
were  but  one-half  to  three-quarters  of  an  inch  long. 
No  misses  occurred,  except  from  those  sets  held  in  the 
cellar.  It  seems  probable  that  each  variety  may  have 
its  own  optimum  temperature,  as  conditions  were  uni- 
form for  both  varieties.  Eighteen  hills  were  used  in  a 
plat,  and  Table  V.,  on  page  59,  shows  the  results. 

Another  great  advantage  in  sprouting  is  that  it 
gives  an  opportunity  to  note  variation  and  "rogue" 
the  variety.  Almost  every  variety  shows  a  difference 
in  the  sprout,  either  in  color  or  habit  of  growth;  one 


CONSIDERATIONS    OF    SEED 


59 


may  have  a  white,  spindly  stem,  which  becomes  green 
on  exposure;  another  a  short,  sturdy  stem,  which  be- 
comes bright  red;  while  another  may  be  purple,  and  so 
on.  So  far  I  have  found  the  ' '  sprouting  stage  ' '  the 
most  reliable  one  at  which  to  note  differences  in  varie- 
ties, and  varieties  of  potatoes  may  be  distinguished  as 
readily  as  varieties  of  other  crops. 

TABLE   V 


SIR  WALTER  RALEIGH 

CARMAN  NO.  3 

No. 
of 
Plat 

Method  and 
Temperature 
of  Germination 

No.  of  Misses 
out  of 
Eighteen  Sets 

YIELD 

No.  of  Misses 
out  of 
Eighteen  Sets 

YIELD 

No.  of  Tubers 

^ 

II 

^ 

Percentage 
Increase, 
in  Yield 

No.  of  Tubers 

.|2 
^ 

Percentage 
Increase 
in  Yield 

Lbs. 

Lbs. 

2 

Cellar  50-60°  F... 
Cold  Frame  bot- 

2 

118 

I7-50 

o 

93 

15-25 

tom  heat  80°  F. 

sash  off  
Cellar  50-60°  F  .  . 

0 

130 

17.00 
16.20 

0.9 

o 

125 
9 

26.5 

73-5 

4 

Barn,  near  open 

window        45- 

5 

75°F  ... 
Cellar  50-60°  F.  .  . 

o 

0 

ICO 

140 

20.12 
I7-50 

19.4 

o 
o 

122 
107 

21.25 
16.25 

36.9 

6 

Greenhouse    78- 

9o°F  

0 

IJ- 

20.25 

22.0 

o 

8s 

16.25 

4.1 

7 

Cellar  50-60°  F.  .  . 

0 

l>1 

15-75 

I 

i'7 

15.00 

The  disadvantage  of  the  system  of  sprouting  pota- 
toes is  that  the  tubers  must  be  planted  by  hand  on  ac- 
count of  the  liability  of  knocking  the  sprouts  off  if 
passed  through  the  planter.  There  are  many  local 
markets  in  the  United  States  poorly  supplied  with 
early  potatoes,  and  to  suppl)r  such  a  small  area  of  the 
crop  could  be  profitably  handled  as  above  described. 
A  distinction  must  be  noted  between  the  above  method 


60  THE   POTATO 

and  the  slovenly  practice  of  many  who  allow  their 
seed  tubers  to  send  out  long  sprouts  before  planting, 
which  are  either  broken  off  intentionally  before  or 
unintentionally  during  planting.  This  practice  cannot 
be  too  strongly  condemned. 

The  Trays  may  be  made  small  to  hold  40  pounds 
of  potatoes,  with  a  handle  running  lengthwise  across 
the  top,  or  to  contain  80  to  100  pounds,  and  handled 
by  two  men,  when  the  handles  run  across.  The  lum- 
ber for  the  trays,  ready  sawn  in  lengths,  should  be 
purchased  at  from  five  cents  to  ten  cents  per  tray, 
according  to  size. 

Whole  Sets  vs.  Cut  Sets.— Considerable  atten- 
tion has  been  given  to  the  advisability  of  cutting  seed 
tubers.  The  question  is  wholly  a  financial  one,  as  in 
an  average  year  with  an  ordinary  late  variety  the 
weight  of  the  seed  planted  is  of  more  importance  than 
whether  it  is  whole  or  cut.  Early  varieties  do  not  do 
so  well  when  cut,  and  varieties  with  white  flowers 
seem  to  be  softer  in  texture  and  more  liable  to  failure, 
if  cut,  than  those  with  purple  or  colored  blossoms. 
Some  varieties  cannot  be  cut  with  profit,  owing  to  lack 
of  bud-producing  eyes. 

The  labor  of  cutting  is  often  greater  than  the  cost 
of  the  extra  seed.  When  seed  is  expensive,  as  when  a 
variety  is  new,  it  is  wise  to  cut  as  far  as  possible  to 
secure  the  largest  possible  yield  in  the  least  time,  but 
this  course  must  be  followed  by  selection,  or  rapid 
deterioration  of  the  variety  will  result.  A  potato  cut 
into  single-eye  pieces,  and  each  piece  planted  in  a 
hill,  will  give  a  greater  yield  than  it  would  had  it  been 
planted  whole. 


CONSIDERATIONS   OF   SEED  6 1 

Time  to  Cut. — Formerly  it  was  advised  to  cut  the 
potatoes  a  few  days  before  planting.  Generally  speak- 
ing, this  is  a  mistake.  Zavitz '  reports  as  the  result 
of  hundreds  of  trials,  during  a  period  of  eight  years, 
that  potatoes  cut  the  da)'  of  planting  gave  8  bushels 
per  acre  heavier  yield  than  those  cut  four  to  six  days 
before  planting.  Similar  results  were  obtained  at  the 
Montana  Experiment  Station.4 

Size  of  Seed. — It  is  a  matter  of  general  observa- 
tion, supported  by  experiments,  that  large  seed  usually 
insures  a  larger  yield  than  small  seed.  This  may  be 
due  to  the  greater  amount  of  nourishment  furnished  to 
the  young  plants,  which  enables  them  to  make  stronger 
growth,  and  to  the  greater  hereditary  vigor  possessed 
by  such  tubers.  Good-sized  seed  is  especially  desira- 
able  on  light  soils,  and  'for  early  maturing  varieties. 
Smaller  seed  from  vigorous  plants  may  be  as  satisfac- 
tory with  late  varieties,  owing  to  their  longer  period 
of  growth.  The  advisability  of  using  large  or  small 
seed,  cut  or  whole,  depends  largely  upon  the  cost  of 
the  seed,  the  season,  the  culture  given,  and  the  price 
realized  when  harvested.  Generally  speaking,  tubers 
weighing  two  to  three  ounces  make  the  most  profitable 
seed,  as  they  are  worth  less  for  consumption.  The 
amount  of  experimental  work  which  has  been  under- 
taken to  decide  the  influence  of  the  size  of  the  seed 
tuber  upon  the  yield  is  enormous,  and  only  a  few  ref- 
erences can  be  given  here. 

Fischer,3  of  Germany,  advises   (i)  that  under  ordi- 


1  Out   Agr.  College  and  Harm  Report,  1898,  p.  158;  1902,  p.  127. 

=  Moil.  Hul.  9,  p.  21.  '  K.  S.  R.,  IX.,  p.  331;  X.,  pp.  361-367. 


62  THE   POTATO 

nary  conditions  large  seed  should  be  used,  (2)  on  good 
soils  with  heavy  fertilizing  small  tubers  and  closer 
planting  is  advisable;  but  that  the  small  tubers  shall  be 
the  progeny  of  large  tubers  grown  on  well-cultivated 
and  fertilized  soil,  to  prevent  degeneration.  Tubers 
which  are  small  because  the  parent  plant  had  not  suf- 
ficient vigor  to  produce  any  larger  are  worthless  for 
seed. 

At  Arkansas  Station1  whole  tubers  2  inches  to  3 
inches  in  diameter  yielded  18  per  cent,  more  than  small 
whole  tubers  ^  inches  to  i#  inches  in  diameter,  and 
large  cut  tubers  15.8  per  cent,  more  than  small  cut 
tubers.  At  the  Ontario  Agricultural  College"  the 
largest  yields  for  four  years  in  succession  were  from 
planting  large  seed.  Sets  weighing  one-sixteenth  of 
an  ounce  and  having  one  eye  yielded,  on  an  average, 
for  the  four  years,  44.2  bushels,  while  two-ounce  sets 
having  one  eye  averaged  177.4  bushels  per  acre,  and 
intervening  sizes  of  sets  yielded  in  proportion  to  their 
size.  As  the  result  of  eight  years'  careful  experi- 
ments, this  station  advises  that  large  tubers  be  cut  into 
pieces  weighing  about  two  ounces  each  for  sets.3 

J.  C.  Arthur,4  of  Indiana,  conducted  an  elaborate 
set  of  experiments  for  three  years  to  ascertain  the  rela- 
tion of  the  number  of  eyes  on  the  seed  tuber  to  the 
product.  He  found  that  within  certain  limits  the  yield 
will  increase  with  an  increase  in  the  weight  of  the  set, 
and  that  the  exact  number  of  eyes  per  cutting  is  rela- 
tively unimportant.  With  tubers  of  the  same  weight 
and  variety  the  number  of  shoots  does  not  perceptibly 

1  Ark.  Bui.  50,  p.  28.  »  Ont.  Agr.  Col.  Report,  1898,  p.  156. 

*  Ont.  Agr.  Col.  Report,  1932,  p.  126.     *  Ind.  Bui.  42. 


CONSIDERATIONS   OF  SEED  63 

increase  with  the  increase  of  eyes  on  the  tuber.  Seed 
tubers  weighing  i^4  ounces  and  carrying  8  to  10  eyes 
sent  up,  on  an  average,  5.5  stalks  per  tuber,  while  seed 
tubers  weighing  3  ounces  and  having  14  to  18  eyes 
sent  up,  on  an  average,  11.3  stalks  per  tuber.  Bisect- 
ing an  eye  tends  to  increase  the  number  of  stalks,  be- 
cause each  eye  is  usually  a  collection  of  buds,  and  some 
would  be  left  uninjured  on  each  piece.  The  number 
of  stalks  sent  up  tended  to  increase  with  the  size  of  the 
seed  tuber,  and  the  yield  increased  with  the  increase  in 
number  of  stalks. 

The  Virginia  Experiment  Station  '  reports  that  large 
seed  cannot  be  used  at  a  profit,  while  small  seed  is  not 
recommended,  but  that  sound  tubers  of  the  size  of  a 
hen's  egg  and  upward  are  proper  seed. 

Green,2  of  Ohio,  found  that  crops  from  whole  seed 
mature  a  few  days  earlier  than  from  the  same  sized 
seed  cut  in  two,  and  that  small  cuttings  require  the 
soil  to  be  in  better  condition  than  large  cuttings,  or 
whole  potatoes,  in  order  to  secure  a  good  stand  and  a 
profitable  crop. 

Amount  of  Seed  Per  Acre — Cost  and  Influ- 
ence on  Yield. — Plumb,3  of  Tennessee  Experiment 
Station,  found  the  largest  seed  tubers  to  be  most  pro- 
ductive and  the  least  profitable,  while  those  varying  in 
weight  from  one  to  three  ounces  were  most  profitable. 

At  Kentucky  Experiment  Station4  the  amounts 
planted  varied  from  six  bushels  per  acre  when  medium- 
sized  seed  were  cut  to  two  eyes  to  48  bushels  per  acre 
where  large  whole  potatoes  were  planted.  At  the 


1  Va.  Bui.  8,  p.  3.  2  Ohio  Second  Series  Bui.,  Vol.  III.,  I.,  p.  14. 

»Tenn.  Bui.,  Vol.  III.,  I.,  p. 6.     *Ky.  Bui.  22,  p.  136. 


64 


THE   POTATO 
TABLE    VI 


A  mount 
of  seed 
peracre. 
Bushels 

Weight 
of  seed 
tubers. 
Ounces 

Distance 
planted 
apart. 
Feet 

Y 

seed  per 
acre  at 
ISC.  per 
Bushel 

cropper 
acre  at 
4oc.  per 
Bushel 

after 
paying 
for 
Seed 

Bushels 

Number 
of  Tubers 

64 

12-14 

3 

146 

220 

90,980 
135,075 

48.00 
60.75 

58.40 

10.40 
17-25 

66 

8-10 

195 

118.102 

49-50 

78.00 

28.50 

6-  8 

j  68 

115.273 

39.00 

67.20 

28.20 

37 

4-  6 
3-  4 

g 

108,908 
104,665 

27-75 
I9-50 

63.20 
58.40 

3^9° 

18 

2-  3 

141 

81,328 

13-50 

56.40 

42.90 

11 

1-   2 

128 

67,184 

8.25 

51.20 

42.95 

Michigan   Experiment   Station1    three   varieties   were 
tested,  with  results  as  shown  in  the  following  table: 


TABLE   VII 


SI/-K   OF   SEED 

per 

I  of  seed 

Yield 
per  acre 

Net  yield 
in  excess  of 
seed 

Net  gain 
front 
using 
halves 

Bushels 

Lbs. 

Bushels 

Bushels 

Bushels 

Halves  

20 

19 

317 

297 

Quarters  .... 
Eighths  

9 

5 

54 
44 

254 

221 

244 
215 

§ 

Single  eyes  .   .   . 
Whole  tubers  .  . 

4 
4i 

10 

40 

178 
293 

174 
251 

9 

The  writer  has  found  from  seventeen  to  twenty 
bushels  to  be  necessary  to  furnish  a  good  seeding,  and 
others  have  advocated  the  same  amount,1  although  a 
less  quantity  is  frequently  mentioned  as  satisfactory. 

A  compilation2  of  experiments  made  at  thirteen 
stations  to  determine  the  proper  amounts  of  seed  shows: 

i.  Within  ordinary  limits,  an  increase  in  seed  pro- 
duces a  marked  increase  in  total  yield  and  marketable 
potatoes. 


Mich.  Bui.  57,  p.  18. 


J  Mich.  Bui.  93,  pp.  5,  6. 


CONSIDERATIONS  OF  SEED  65 

2.  An  increase  in  the  size  of  the  seed  from  one  eye 
to  half  a  potato  produces  an  increase  in  the  net  value 
of  the  crop. 

A  comparison  of  the  half  potato  with  the  two  e3^es 
shows  that : 

1.  For  the  total  yield  (large  and  small)  of  95  ex- 
periments, 76  are  in  favor  of  the  half  potato  and  19 
in  favor  of  two  eyes. 

2.  For  marketable  yield  (total  less  small)  of  73  ex- 
periments, 58  are  in  favor  of  the  half  potato  and  15  in 
favor  of  the  two  eyes. 

3.  For  net  marketable  yield  (marketable  less  amount 
of  seed)  of  30  experiments,  23  are  in  favor  of  the  half 
potato  and  7  in  favor  of  the  two  eyes. 

4.  For  net  value  of  crop  (value  of  crop  less  value  of 
seed)  of  30  experiments,   22  are  in  favor  of  the  half 
potato  and  8  in  favor  of  two  eyes. 

A  comparison  of  the  whole  potato  with  the  half 
potato  shows  that : 

1.  For  the  total  yield  (large  and  small)  of  54  ex- 
periments, 46  were  in  favor  of  the  whole  potato  and  8 
in  favor  of  the  half  potato. 

2.  For  the  marketable  yield  (total  less  small)  of  42 
experiments,  36  were  in  favor  of  the  whole  potato  and 
6  in  favor  of  the  half  potato. 

3.  For  the  net  marketable  yield   (marketable  less 
amount  of  seed)  of  13  experiments,  7  are  in  favor  of  the 
whole  potato  and  6  in  favor  of  the  half  potato. 

4.  For  the  net  value  of  crop  (value  of  marketable 
less  value  of  seed  planted)  of  12  experiments,  7  are  in 
favor  of  the  whole  potato  and  5  in  favor  of  the  half 
potato. 


66  THE   POTATO 

The  Value  of  Bud  and  Stem  Ends  and  the 
Middle  of  the  Tuber  for  Seed. — Many  ideas  have 
prevailed  as  to  the  relative  values  of  different  parts  of 
the  tuber  for  seed.  Some  growers  advocate  the  re- 
moval of  one  end  or  the  other,  but  thus  far  the  ex- 
periments conducted  at  a  dozen  stations,  including  such 
varying  points  as  Illinois,1  New  Jersey,2  and  North 
Dakota3  Experiment  Stations,  show  that  there  is  no 
material  difference  uoticable  in  yield  that  could  be  at- 
tributed to  the  different  pieces,  and  that  the  two  ends 
of  a  tuber  are  practically  of  equal  value. 

Viability. — The  buds  of  tubers  vary  considerably  in 
their  ability  to  grow,  and  the  same  is  true  of  the  tubers 
themselves.  Goff,  of  Wisconsin,4  when  using  the  vari- 
ety Burbank,  obtained  a  stand  varying  from  88  to  100 
per  cent,  of  the  potatoes  planted.  The  importance  of 
proper  moisture  content  of  the  soil  is  shown  by  the 
results  reported  in  the  following  table  by  Woods,  of 
Maine:5 

TABLE  VIII 

VARIETY  STAND 

Percentage  of  Cuttings 
that  Produced  Plants 
Rose         22 

Early  Michigan 46 

Hulett's  Rust  Proof 37 

Mill's  Mortgage  Lifter 20 

Green  Mountain 61 

New  Queen I 

Polaris 55 

Maggie  Murphy 50 

Irish  Cobbler 65 

Early  Ohio 57 

Gem  of  Aroostock 28 


Bovee 


55 


'  111.  Bui.  40,  p.  132.     «  N.  J   Report,  1898,  p.  308.     »  N.  D.  Report,  1901, 
pp.  40-42.      *  Wis.  Report,  1897,  p.  306.       6  Me.  Bui.  98,  p.  183. 


CONSIDERATIONS   OF  SEED 


This  poor  stand  was  largely  due  to  a  very  dry  spell 
in  May  and  June,  and  the  differences  observed  in  the 
various  varieties  may  be  due  to  the  vitality  of  the  vari- 
eties themselves,  or  to  the  way  in  which  they  were 
grown  and  stored,  or  to  both  causes.  Girard,  of 
France,  summarized  his  experiments  some  time  ago, 
showing  the  influence  of  the  size  of  the  tuber  upon  the 
' '  stand  ' '  and  yield. 

TABLE  IX 


WEIGHT   OF  SEED 

Percentage 
Number  of 
Failures 

Percentage 
Weight  of 
Crop 

i  —  Tubers   3.5  oz.  each,  planted  whole    .... 
2  —  Tubers   3.5  oz.  each,  cut  into  two  portions 
3  —  Tubers   7.0  oz.  each,  cut  into  two  portions  . 

'   6.0 

12.0 
10.5 

100.00 

69.36 
82  oo 

5  —  Tubers    1.75  oz.  each,   two  tubers   planted 
together  
6  —  Tubers    r.o  oz.  each,  three  tubers  planted 

3-7 

95.36 

89.12 

The  yield  of  No.  2  is  not  comparable  with  the 
others,  because  the  same  weight  of  seed  was  not  used. 
Plats  i  and  3  are  probably  the  best  to  use  for  ordinary 
consideration,  and  would  show  that  from  90  to  95  per 
cent,  of  the  tubers  planted  should  grow,  but  it  is  a 
well-known  observation  that  under  adverse  conditions 
— as,  a  dry  season,  ill-fitted  land,  etc. — a  small  cutting 
is  not  so  likely  to  grow  as  a  whole  tuber. 

The  diagram  (Fig.  16)  shows  that  with  Carman  No. 
3,  where  twenty  plats  were  noted,  there  were  3  chances 
in  20  that  the  germination  of  the  tubers  and  stand 
would  be  looper  cent.,  and  that  it  is  much  more  likely 
to  be  between  91  and  98  per  cent,  than  any  other 


68 


THE  POTATO 


A 

/ 

\ 

/ 

\ 

/ 

\ 

n 

/ 

\ 

/ 

\ 

/ 

\ 

/ 

\ 

inCwi   jf, — DIAGRAM    SHOWING   STAND   OK   TWENTY   PLATS   OF 

CARMAN    NO.     3     I'OTATOKS  ' 

The  percentage  stand  is  shown  on  the  base-line.     The  hight  of  the  cuive 
from  the  base-line  shows  the  actual  number  of  plats. 


AAA 


AA 


A  AA 


90  '      85   "      80 75  '70         65" "  60" 

Kl<;.   17 — DIAGRAM    SHOWING   STAND   OF   THIRTY-SI^   PLATS 

OK    EARLY    TRUMBU1.L    POTATOES1 

The  percentage  stand  is  shown  on  the  base-line.     The  hight  of  the  curve 
from  the  base-line  shows  the  actual  number  of  plats. 

number,    although  the  average  as  usually  worked  out 
would  show  93.5  per  cent. 

With  Early  Trumbull,  using  seed  showing  the  rosette 
disease  (Rhizoctonia  solanf)  and  some  not  showing  it, 
treated  with  various  fungicides,  the  average  germina- 


1  From  data  in  Ohio  Bui.  145,  p 


CONSIDERATIONS  OP  SEED  69 

ting  power  for  36  plats  is  73. 8  per  cent.  Yet,  here  again 
this  does  not  convey  a  true  impression,  as  on  six  plats 
all  of  the  tubers  germinated,  and  the  table  shows  that' 
there  is  a  greater  chance  of  securing  a  stand  of  between 
83  and  98  per  cent,  than  lower.1 

The  viability  of  tubers  is  injured  or  ruined  if  they 
heat  or  sweat  to  any  extent;  hence,  if  they  have  been 
treated  with  a  solution,  as  for  scab,  it  is  essential  that 
they  be  planted  at  once  or  spread  thinly  to  dry.  Po- 
tatoes may  be  ruined  for  seed  purposes,  if  frozen,  or  if 
shipped  in  bags  or  barrels  which  have  contained  sub- 
stances injurious  to  the  buds — as,  sugar,  nitrate  of  soda, 
etc. ;  and  even  moving  them  on  the  farm  in  unwashed 
sugar-bags  has  been  found  to  be  dangerous.  Immer- 
sion in  water  for  more  than  a  day  may  destroy  the 
buds,  and  probably  cause  the  tuber  to  decay  in  a  few 
days.  By  this  means  potatoes  have  been  destroyed  in 
pits  and  in  the  field  when  floods  have  occurred.  Soak- 
ing them  in  too  strong  a  solution  of  formalin  or  other 
preservative  is  liable  to  reduce  viability,  because  the 
formalin  tends  to  preserve  the  tuber  and  prevent  its  de- 
composition. 

Potatoes  which  have  been  subjecl  to  diseases  may  be 
weakened  and  their  vitality  impaired. 


From  data  in  Ohio  Exp.  Sta.  Bui.  145,  p.  21. 


£ 


CHAPTER  •  VII 
VARIETIES 

Selecting  a  Variety. — For  general  farming  it  is 
advisable  to  grow  only  a  few  varieties.  Most  success- 
ful growers  seldom  have  half  a  dozen  growing  for  mar- 
keting, and  usually  one  is  selected  as  more  suitable 
than  the  rest.  The  beginner  is  advised  to  seledl  a 
variety  from  the  more  thoroughly  tested  kinds  that 
have  done  well  in  his  immediate  vicinity  and  on  his  type 
of  soil.  The  seed  should  be  obtained  from  a  reliable 
grower  or  a  responsible  seedsman.  The  importance 
of  growing  the  best  varieties  cannot  be  too  strongly 
emphasized.  To  many  a  potato  is  a  potato,  and  any- 
thing is  used  for  seed.  Such  haphazard  methods 
cannot  survive.  Potatoes  are  grown  for  human  con- 
sumption, and  the  public  taste  must  be  considered. 
Good  quality  and  good  yield  are  required.  In  some 
localities  good  quality  potatoes  appear  to  be  grown  in 
spite  of  adverse  conditions,  but  not  all  of  the  crop  can 
be  produced  in  this  way. 

Some  of  the  points  to  consider  in  selecting  the 
variety  are  : 

1 .  Good  cooking  quality  and  flavor.     This  is  partly 

influenced  by  the  soil,  season,  ability  to  mature 
before  frost,  etc. 

2.  The  yield.     The  late  maturing  varieties  usually 

yield  heavier  than  the  early  varieties.     Yield  is 
influenced,  among  other  things,  by  the  adapta- 
bility of  the  variety  to  the  district  and  soil. 
70 


VARIETIES  71 

3.  Ability  to  resist  diseases.     The  potato  is  so  sub- 

ject to  disease  that  this  is  now  of  prime  impor- 
tance in  a  variety  in  the  Eastern  States,  although 
not  so  important  in  parts  of  the  Trans- Missis- 
sippi area. 

4.  The  color  of  the  skin  and  tuber.     In  the  Eastern 

States  red  varieties  are  not  in  favor  at  present, 
a  white-fleshed  and  white-skinned  tuber  being 
preferred.  In  the  South  red-skinned  varieties 
are  sought.1 

5.  The  nature  of  the  skin.     A  netted,  or  rough,  skin 

is  preferred. 

6.  The  shape.    Some  markets  discriminate  in  favor 

of  a  particular  shape,  the  flat-round  and  oval 
generally  being  popular  shapes. 

7.  The  depth  and  frequency  of  eyes.     Potatoes  with 

deep  and  numerous  eyes  are  not  economical  in 
preparation  for  cooking. 

8.  The  time  of  maturity .     This  is  essential  to  know 

before  planting,  in  order  to  facilitate  the  dis- 
tribution of  farm  work  and  determine  whether 
it  is  likely  to  mature  in  the  locality. 

9.  The  haulm. 

10.  The  leaf. 

1 1 .  The   vigor  of  the  variety.      This   is   important, 

although  it  is  of  equal  importance  to  obtain  a 
vigorous  strain  of  a  variety,  as  wide  variations 
are  noted  in  the  same  variety. 

12.  Tendency  to  make  second  growth. 


>Tex.  Bui.  71,  p.  9. 


THE   POTATO 


13.   Trueness  to  type.      It  is  essential  that  the  seed 
be  as  represented.    As  none  but  an  expert  can 
p  tell  the  different 

varieties    apart, 
seed   should   be 
obtained  from  a 
reliable    grower 
or  a  responsible 
seedsman. 
I.    Cooking  quality 
and  flavor  are  two  of 
the      factors     which 
determine     culinary 
value.        They     are 
distinct.         Cooking 
quality  is  recognized 
in  a  boiled  potato  by 
mealiness  or    soggi- 

FIG.   l8 — SECTION  OF  A  POTATO  OF  ^v,   . 

POOR    COOKING    QUALITY 

P-Envelope,  or  Periderm,  consisting  of  an  to  depend  Upon  the 
inner  and  outer  layer.  P.L- Pigment  layer,  physiological  StrUC- 
where  coloring-matter  of  the  skin  is  found. 

£.C-External  Cortical,  or  Cambium  layer,  ture  OI  the  tuber,  and 
usually  poor  in  starch.  /.C-Internal  Cor-  is  not  necessarily  COn- 
tical.or  Cambium  layer,  rich  in  starch.  EM  .  . 

-External  Medullary  layer,  rich  in  starch.   neCted  With  Chemical 
/.^/•-Internal  Medullary  layer,  or  pith,  or  composition        (FigS. 
water-core,  poor  in  starch.  '       .  . 

The  objectionable  features  of  this  tuber  are  1°,  19)-  A  potato 
large  pith  area  and  lack  of  uniformity  in  showing  Uniformity 
cellular  structure.  Each  layer  is  readily  rec-  .  . 

ognized,  and  each  one  varies  in  the  amount  of  m  the  distribution  OI 
time  required  for  cooking;  hence,  it  is  of  poor  starch  in  the  VanOUS 
cooking  quality.  (Com pare  with  Fig.  19.) 

layers  may  be  con- 
sidered to  be  of  better  quality  than  one  not  showing 
this  uniformity.  Immature  potatoes  tend  to  be  soggy 


VARIETIES 


73 


IM. 


when  cooked.  Mealiness  is  due  to  the  union  of  the 
starch  grains  in  a  cell  into  one  mass,  and  the  rup- 
ture of  the  cell 
walls  during  cook- 
ing. Sogginess 
occurs  when  the 
cell  walls  retain 
their  form.  Opin- 
ions differ  as  to 
what  constitutes 
good  cooking 
quality.  Amer- 
icans like  a  white, 
mealy,  or  floury, 
potato.  The 
French  prefer  a 
yellow,  soggy 
potato  which  re- 
tains its  shape 
when  boiled. 

Good  cooking 
quality  can  be  de- 
termined by  cook- 
ing. The  common 


FIG.   19 — SECTION   OF  A   POTATO   OF 
GOOD   COOKING   QUALITY 

(Compare  with  Fig.  18.) 

The  desirable  features  of  this  tuber  are  well- 
netted  skin,  showing  maturity;  large  Internal 
Cortical  (/.C)and  External  Medullary  (EM.) 
layers,  which  are  rich  in  starch  ;  small  pith 
area  (I.M.),  with  marked  uniformity  in  cellu- 
lar structure.  The  different  layers  nearly  ap- 
proach each  other  in  appearance,  and  cook 
uniformly. 

method  is  to  take 

a  sample  and  steam  or  boil  some  of  the  potatoes. 
When  cooked  the  potato  should  be  dry  and  floury,  free 
from  wetness,  and  readily  break  to  pieces  on  slight 
pressure,  or  be  readily  reduced  to  a  coarse  meal  free 
from  hard  lumps.  The  particles  should  glisten  as 
though  crystalline,  and  the  potato  should  have  a  white 
color,  which  is  retained  when  cold.  Potatoes  which 


74 


THE  POTATO 


are  yellow  when  cooked,  or  turn  dark  or  black,  are 
not  considered  of  good  quality,  even  if  the  flavor  is 
good,  and  can  be  sold  only  to  a  low-class  trade. 
Tubers  must  not  be  hollow  in  the  center,  as  this  gives 
rise  to  a  hard,  dark-colored  core,  which  is  decidedly 
objectionable  if  potatoes  are  to  be  mashed. 

Some  varieties  will  cook  better  if  they  have  been 
kept ;  they  are,  in  other  words,  for  spring  use.  Thus, 
in  New  York,  Carman  No.  3,  White  Star,  and  Doe's 
Pride  come  in  this  category. 

The  flavor  should  be  mild,  and  free  from  earthiness. 

2.  The  yield.  The  average  yield  of  potatoes  from 
one  plant  in  the  United  States  is  about  half  a  pound. 
Having  weighed  the  yield  of  hundreds  of  potato 
plants  during  the  past  year,  we  find  that  in  the  case  of 
Early  Ohio  one  plant  yielded  three  tubers  weighing 
half  an  ounce,  while  another  yielded  thirteen  tubers 
weighing  two  and  a  half  pounds.  The  latter  yield  is 
eighty  times  the  former.  In  late  varieties  plants  yield- 
ing four  pounds  of  tubers  were  found.  In  some  of  the 
recent  English  productions  whole  plats  would  average 
six  pounds  of  tubers  per  plant,  while  individual  plants 
have  yielded  over  twenty  pounds  of  potatoes,  as  man}' 
as  150  potatoes  being  set  on  one  plant.1  These  facts 
emphasize  the  value  of  the  farmer  selecting  seed  him- 
self and  eliminating  the  poor  plants.  All  the  tubers 
from  the  best  plants  should  be  saved  and  planted  sep- 
arately to  produce  the  seed  for  the  following  year. 
The  expenses  of  growing  a  poor  and  a  heavy  crop 
vary  little.  The  only  additional  cost  of  the  latter  is 


1  Gardener's  Chronicle,  Oct.  15,  1904,  pp.  276-278. 


VARIETIES  75 

a  little  more  for  digging.  The  variety  controls  the 
yield  to  a  large  extent,  and  there  is  much  more  like- 
lihood of  obtaining  a  3oo-bushel  crop  from  a  variety 
capable  of  yielding  600  than  from  one  whose  maxi- 
mum yield  is  300  bushels.  This  fadl  is  realized, 
and  the  high  prices  paid  in  recent  years  in  Great 
Britain  for  seed  potatoes  of  good  quality,  heavy  yield- 
ing, and  disease-resisting  varieties  are  legitimate  and 
proper  recompense  to  the  men  who  have  the  skill  to 
breed  such.  These  new  varieties  are  profitable  to 
grow  because  there  is  an  assurance  that  the  crop  will 
yield  well,  and  that  it  will  keep  well;  hence  there  is  an 
opportunity  to  hold  it  until  it  can  be  sold  at  a  profit. 
These  farmers  realize  that  the  best  is  none  too  good, 
and  that  it  is  useless  handling  varieties  that  are  out  of 
date.  The  potato  grower  of  Great  Britain  and  Europe 
must  be  up  to  date  if  he  is  to  stay  in  the  business. 
High-priced  seed  receives  more  care  in  storage  and  is 
handled  more  intelligently,  the  seed-bed  is  better  pre- 
pared, and  the  result  is  better  farming.  The  farmer 
who  grows  such  crops  is  a  more  thoughtful  and  better 
business  man,  as  slovenly  methods  have  to  be  aban- 
doned. 

Yield  is  influenced  by  the  size  and  number  of  tubers 
at  a  root.  Uniformity  and  good  size  are  desired. 
Potatoes  vary  in  size  from  almost  nil  to  six  pounds 
each  or  more.  In  Doe's  Pride  one  plant  set  21  tubers, 
varying  in  size  between  i-io  ounce  and  6^  ounces; 
in  other  words,  one  potato  was  65  times  larger  than 
the  other.  In  the  East  potatoes  over  8  ounces  in 
weight  are  large.  Medium-sized  tubers  of  merchant- 
able value  vary  between  four  and  eight  ounces.  Sec- 


76 


THE   POTATO 


onds  between  two  and  four  ounces,  and  tubers  less 
than  this  weight,  are  hardly  worth  picking  up. 

3.  Ability   to  resist  diseases.      No  varieties   can  be 
termed  "disease  proof,"  but  many  varieties  are  better 
disease-resisters  than  others.      Stuart,  of  New  Hamp- 
shire, found  that  the  variety  Hulett's  Rust  Proof  was 
the  only  one  that  was  disease-resistant  out  of  several 
varieties,  although  the  varieties  Dakota   Red,  Green 
Mountain,   New  Queen,  and  Enormous  showed  some 
resistance.     Hulett's  Rust  Proof  falls  below  the  re- 
quirements in  other  respects  and  is  of  little  value,  and 
in  Minnesota  has  been  found  to  be  subject  to  disease. 
At  Ontario  Agricultural  College,  Carman  No.  3  and 
Stray   Beauty   resisted   disease  well.     At   Minnesota 
Experiment  Station,  Rural  New  Yorker  and  Sir  Wal- 
ter Raleigh  showed  some  resistance.4 

4.  The  color  of  the  skin  and  tuber.      Many  of  the 
colored-skinned  varieties  of  potatoes,  and  those  show- 
ing a  blush  of  pink — as,  the  Beaut}'-  of  Hebron,  Early 
Rose,  etc. — belong  to  a  type  which  have  white  blooms. 
They  are  generally  early  maturing,  rather  liable  to  dis- 
ease, and  of  good  quality,  according  to  the  American 
standard.    The  colored-skinned  early  varieties  are  gen- 
erally more  readily  sold  than  the  late  ones,  although 
in  some  districts  colored-skinned  potatoes  are  not  ob- 
jected to  on  the  market.     All  colored-skinned  potatoes 
are  not  deficient  in  vigor.     Some  are  among  the  best 
disease-resisting   and   best-flavored  varieties,  but  the 
red  color  of  some  weak  varieties  has  rendered  some 
growers  skeptical  of  all. 


1  Minn.  Bui.  87,  p.  2.  i  Minn.  Bui.  87,  p.  jo. 


i  - 

3  * 


I 


78  THE   POTATO 

5.  The  nature  of  the  skin .     The  skin  may  be  thick, 
medium,  or  thin.     Some  growers  claim   that   thick- 
skinned  varieties  are  of  better  quality  than  thin-skinned 
ones,    but  such  correlation   does    not    always    exist. 
Potatoes  grown  on  sandy  soils  usually  have  smoother 
skins  than  those  grown  on  heavy  loams.     Some  va- 
rieties develop  a  netted,  or  rough,  skin  as  they  mature 
in   storage,    although   such   may   not  be  apparent  at 
harvest-time.      The   rough,  or  netted,  skin  in  these 
cases  appears  to  denote  maturity,  and  this  may  account 
for  the  common  idea  that  a  rough-skinned  potato  is  of 
good  quality.     The  size  and  type  of  netting  (Fig.  20) 
varies   with   the   variety,    and   the   conditions   under 
which  it  is  grown. 

6.  The  shape.      Most  of  the  recent  introductions, 
exclusive  of  the  Early  Rose  type,  have  had  a  tendency 
to  partake  of  the  flat-round  or  oval  (Fig.  21).     These 
shapes  have  been  sought  because  such  potatoes  appear 
to  be  of  better  quality  consistent  with  an  economical 
shape  and  shallow  eyes.     The  probable  explanation  is 
that  in  a  flat-round  or  thinnish  potato  there  is  a  greater 
surface  in  proportion  to  the  bulk.     The  greater  the 
surface  the  larger  the  percentage  of  the  tuber  taken 
up  in  the  cortical  layer  and  outer  medullary  layer  (Fig. 
18).     These  are  the  starch-bearing  areas,  and  as  they 
are  increased  the  inner  medullary  layer,  or  pith,  which 
has  little  starch,   is  diminished,    thus   rendering  the 
potato  more  uniform.     Whatever  shape  is  desired  can 
be  be  obtained,  but  a  potato  should  be  true  to  shape. 
The  tendency  of  a  tuber  to  become  pointed  or  drawn 
out  at  the  tip  or  butt  end,  especially  if  the  variety  is 
a  flat-round  or  round,  indicates  lack  of  vigor  (Fig.  21). 


VARIETIES 


79 


7.  Depth  and  frequency  of  eyes.    Deep  eyes  (Fig.  21), 
to  some  extent,  are  regarded  as  associated  with  robust- 


FIG.    21 — THREE    FAVORITE    SHAPES    OF    POTATOES 
(Upper  row,  the  broad  surface  ;  lower  row,  the  narrow  surface.) 
Beginning  on  the  right,  the  small  one  is  a  flat-round;  the  center  one,  kid- 
ney; the  largest  one,  on  the  left,  elongated  oval.    Notice  the  shallow,  wide 
eyes  on  the  latter;  they  are  the  most  desirable.    The  eyes  of  the  flat-round 
are  too  deep. 

ness  and,  frequently,  coarseness.  They  are  wasteful 
in  peeling.  Deep  eyes  tend  to  hold  moisture,  which 
hastens  decay  when  the  potatoes  are  stored. 

8.   Time  of  maturity.     In  the  Northern  States  pota- 


So 


THE   POTATO 


toes  are  classified  into  early,  medium  or  second  early, 
and  late  varieties,  according  to  the  time  they  take  to 
reach  maturity.  Early  varieties  may  mature  in  70  to 


FIG.  22— THE  IMPORTANCE  OF  HAVING  UPRIGHT  HAULM  AND 
PRESERVING  THE  FOLIAGE  IS  NOT  SUFFICIENTLY  APPRECIATE!* 
Plant  photographed  early  in  September,  1904,  when  many  others  near  were 
dead  (C.  V.  Harm).  Upright  haulm  facilitates  late  cultivation  and  spray- 
ing. The  foliage  dries  quickly,  and  then  is  not  so  favorable  for  the  growth 
of  spores  of  rot. 

90  days  after  planting;  second  .ear lies,  in  90  to  130 
days,  while  late  varieties  may  continue  to  grow  for 
200  days. 

9.  The  haulm.  The  haulm  and  leaf  are  receiving 
more  attention  to-day  than  formerly.  The  size  of 
haulm  has  an  influence  upon  the  distance  apart  of 
planting.  L,arge  haulm  is  more  trouble  to  spray,  re- 


VARIETIES  8 1 

quiring  more  solution,  and  it  is  always  lying  over  the 
ground  when  the  last  spraying  ought  to  be  given,  and 
is  in  the  way  at  lifting-time,  whether  the  potatoes  are 
raised  by  hand  or  digger.  Modern  breeders  aim  to 
produce  a  short  haulmed,  upright,  heavily  leaved  top, 
because  the  upright  habit  of  growth  (Fig.  22)  is  more 
likely  to  keep  clear  of  disease  than  a  spreading  habit, 
owing  to  water  being  shed  from  the  former  more  read- 
ily than  from  the  latter,  and  not  offering  a  foothold  to 
the  disease  spores  (Fig.  37).  Plants  whose  branches 
lie  on  the  ground  are  more  liable  to  disease  because 
they  cover  a  greater  area,  their  leaves,  touching  the 
ground,  are  almost  always  damp  from  contact  with  it, 
and  sun  and  wind  cannot  so  readily  reach  them.  Very 
tall  haulmed  varieties  are  readily  beaten  down  by 
storm  and  wind,  and  in  this  state  they  cannot  dry  so 
readily;  hence,  they  fall  in  a  clammy  mass,  very  favor- 
able for  the  growth  of  disease  spores. 

Varieties  with  strong,  hardy  haulm  suffer  less  from 
spring  frosts.  L,ate  varieties  usually  have  taller  haulm 
than  first  early  varieties.  Some  varieties  make  their 
heaviest  growth  of  foliage  late  in  the  season,  and  in 
this  way  are  not  so  subject  to  attacks  of  early  blight. 

10.  The  leaf.  The  British  disease-resisting  varieties 
have  hard,  thick  leaves.  Whether  the  thickness  of  the 
leaf  is  an  important  factor  in  their  resistance  to  rot  (Phy- 
tophthora  infestans}  is  not  determined.  The  fact  that 
spraying  the  upper  surface  of  the  leaf  tends  to  prevent 
blight  would  seem  to  show  that  access  to  the  inside  of 
the  leaf  is  obtained  by  growth  through  the  cell  walls 
as  well  as  through  the  stomata,  on  its  under  surface. 
If  this  be  true,  then  the  thickening  and  hardening 


82  THE   POTATO 

of  the  cuticle  and  the  palisade  cells  (Fig.  34),  or 
thick  cells  on  the  upper  surface  of  the  leaf,  will  no 
doubt  prevent  many  spores  from  reaching  the  inside 
cells  of  the  leaf.  They  may  germinate  on  the  surface, 
but  not  enter,  unless  they  find  some  place  where  the 
leaf  has  been  injured.  The  punctures  of  the  flea- 
beetles  are,  on  this  account,  of  great  importance,  as 
they  furnish  an  entrance  to  the  inner  cells  (Fig.  40). 

N.  A.  Cobb,  of  Australia,  has  shown  that  in  the 
case  of  wheat  the  varieties  most  resistant  to  rust  (Puc- 
cinia  graminis  and  P.  rubigo  vcra),  none  being  abso- 
lutely resistant,  have  narrow,  stiff,  upright  foliage, 
while  those  most  liable  to  attacks  have  broad,  flabby, 
and  pendant  foliage.  In  the  plants  resistant  to  rust 
the  cuticle  of  the  leaf  is  much  thicker  than  in  the 
others,  and  is  so  thick  that  the  rust  spores,  when  they 
germinate  on  the  outside  of  the  leaf,  cannot  penetrate 
it,  or  if  they  do  succeed  in  entering  the  leaf  through 
stomata,  the  threadlike  growths  of  the  parasite  cannot 
rupture  the  cuticle  wall  to  fructify  ;  and,  further,  some 
wheats  have  stomata  so  narrow  and  are  so  well  cov- 
ered with  wax  that  the  germinating  threads  of  the 
rust  spore  fail  to  enter  every  time.  These  circum- 
stances seem  to  support  the  claim  that  the  tough,  thick- 
walled,  hard,  dry  leaf  is  the  one  to  select  for  disease- 
resistant  powers.  It  has  been  observed  that  plants  of 
the  potato  family  having  this  type  of  leaf  are  fairly  free 
from  fungus  leaf  diseases.  It  is  essential  that  the 
leaves  of  the  potato  be  abundant  to  insure  a  good  yield. 

1 1 .  The  vigor  of  the  variety.  Vigor  is  the  power 
stored  in  a  plant  which  enables  it  to  overcome  difficul- 
ties at  different  periods  of  growth.  A  variety  must 


VARIETIES  83 

have  vigor.  If  not,  it  may  fail  to  establish  itself  dur- 
ing the  early  part  of  its  career,  being  a  shy  budder  ; 
it  may  be  readily  injured  by  frost,  heat  or  cold, 
drouth  or  a  wet  period,  and,  having  little  recuperative 
power,  will  give  small  returns  for  the  labor  bestowed 
upon  it.  If  it  survives  to  tuber- formation  time  it  will 
probably  fail  then.  Plants  or  varieties  showing  lack 
of  vigor  must  be  discarded.  Some  varieties  have  short 
staying  power;  they  appear  to  be  vigorous  for  one  or 
two  years,  and  then  suddenly  collapse.  Others  have 
great  staying  power — as,  Early  Rose,  which  has  been 
prominent  for  over  forty  years. 

The  statement  is  sometimes  made  that  modern  vari- 
eties are  not  so  long-lived  as  their  ancestors — that  they 
are  deficient  in  staying  power.  If  the  statement  were 
true,  it  might  be  explained  by  saying  that  new  vari- 
eties are  produced  more  frequently,  and  that  on  account 
of  their  heavier  yielding  power  or  better  quality  they 
displace  the  old  ones.  The  facts  seem  to  show  that 
modern  potato  breeders  have  more  than  maintained 
vigor  and  staying  power.  Hays,  of  Minnesota,  and 
others,  place  the  life  of  a  good  modern  variety  at  about 
thirty  years.  This  seems  to  be  accepted  by  many, 
both  here  and  abroad.  Dr.  Hunter,  of  England,  in 
his  ' '  Geological  Essays, ' '  '  writing  about  one  hundred 
years  ago,  states  ' '  that  varieties  continue  in  vigor 
about  fourteen  years,  after  which  the  produce  gradually 
declines."  Shirreff  and  T.  A.  Knight  held  similar 
views ;  the  latter  wrote 2  that  ' '  not  a  single  healthy 


I  "Geological  Essays,'1  Exp.  14,  p.  348. 

II  Hort.  Trans.,  Vol.  I.,  and  Miller's  "  Gardeners'  Dictionary,"  ed.   1807, 
1  Potatoes." 


84 


THE  POTATO 


plant  of  any  sort  of  potato  that  yields  berries,  and 
which  was  in  culture  twenty  years  ago,  can  now  be 
produced."  So  late  as  1838  this  idea  was  accepted  by 
the  horticulturists  of  England.1  It  is  interesting  to 
note  that  the  average  yield  of  potatoes  in  England  a 
hundred  years  ago  is  stated  to  vary  between  185  and 
300  bushels,  and  sometimes  440  bushels,  per  acre. 
The  average  yield  to-day  is  about  230  bushels,  but 
some  growers  produce  750  bushels  per  acre  frequently. 
The  average  improvement  in  the  quality  of  the  tubers 
is  greater  than  the  average  improvement  in  yield. 
Formerly  the  potatoes  were  grown  largely  for  stock, 
and  were  of  poor  flavor  and  bad  cooking  quality. 

Some  new  varieties  make  vigorous  growth,  and,  be- 
coming bark-bound,  the  skin  cracks.  Such  varieties 
are  regarded  as  of  coarse  and  inferior  quality,  and  lack- 
ing in  appearance.  This  character  may  be  eliminated 
by  judicious  selection.  Deficiency  in  vigor  is  indi- 
cated by  the  formation  of  misshapen  tubers  drawn 
out  at  either  end,  the  presence  of  second  growth,  weak 
buds,  lack  of  uniformity  in  texture — as,  hardness  at 
the  ends  of  the  tubers  when  cut,  especially  brittleness 
of  texture.  Tubers  showing  any  such  characteristics 
should  not  be  planted. 

When  potatoes  are  planted  15  inches  apart  in  36- 
inch  rows,  there  are  11,616  plants  per  acre.  If  each 
plant  had  sufficient  vigor  to  yield  three  tubers,  each 
weighing  half  a  pound,  or  four  weighing  six  ounces 
each,  a  yield  of  290  bushels  of  salable  potatoes  per 
acre  is  assured.  No  one  can  afford  to  use  seed  of  less 
vigor  than  this. 

1  Don's  "Gardeners'  Dictionary,"  1838,  Vol.  IV.,  pp.  400-406. 


VARIETIES  85 

12.  Tendency  to  make  second  growth.    Second  growth 
(Fig.  38)  is  most  prevalent  in  a  season  when  drouth 
is  followed    by  a   wet  period.      The    drouth  checks 
the  development  of  the  tubers,  causing  them  to  begin 
to  mature,  while   the  subsequent  wet  period  restarts 
growth.     If  one  variety  or  a  plant  does  not  show  any 
such  abnormal  growth,  it  is  regarded  as  being  more 
vigorous;  hence,  other  things  being  equal,  such  should 
be  used   for  seed,    and  all  showing  second    growth 
should  be  rejected.     Abnormalities  in  shape  may  be 
due  to  contact  with  stones  or  hard  lumps. 

13.  Triteness  to  type.     This  may  be  viewed  as  em- 
bracing several  considerations.     In  new  varieties  there 
is  always  more  or  less  tendency  to  lose  the  features  for 
which  the  variety  has  been  selected.     The  type  is  then 
said  to  be  insufficiently  fixed,  and  often  those  which 
depart  from  the  type  degenerate.     In  such  cases  selec- 
tion must  be  continued. 

Many  varieties  are  deliberately  or  unintentionally 
sold  for  something  else.  Mixtures  of  varieties  are 
sold  as  one.  Good  varieties  are  often  renamed  and 
sold  by  unscrupulous  seedsman  and  others  as  some- 
thing new.  There  is  considerable  duplication  of 
varieties  of  potatoes;1  thus,  Brooks,  of  Massachusetts,4 
believes,  after  growing  the  folio  wing  varieties,  that  King 
of  the  Earliest  and  Early  Ohio,  Salzer's  Earliest  and 
Bliss  Triumph,  Mills'  Banner  and  Livingston  Banner 
are  identical,  and  that  White  Beauty  and  Cambridge 
Russet  differ  but  slightly.  Mills'  Mortgage  Lifter  is 
often  sold  as  Burpee's  Extra  Early.  Some  dealers 


>  Wyo.  Bui.  32,  p.  65.  »  Hatch  (Mass.)  Sta.  Report,  1899,  p.  81. 


86  THE   POTATO 

have  been  known  to  deliberately  rename  a  well-known 
variety  and  sell  it  as  their  own,  and  as  a  new  and 
heavy  yielding  variety. 

Dakota  Red  is  sold  for  Bliss  Triumph,  although  in- 
ferior in  quality.  The  above  is  not  a  complete  list,  but 
will  show  that  this  state  of  affairs  exists,  and  empha- 
sizes the  importance  of  dealing  with  a  firm  who  have  a 
reputation  to  lose. 

Testing  Varieties. — It  is  advisable  to  secure 
copies  of  experiment-station  literature  and  papers  in 
which  variety  trials  are  reported.  The  best  variety 
for  one  soil  is  not  the  best  for  another.  The  only  way 
to  have  the  best  is  to  make  a  trial  with  small  quanti- 
ties of  different  varieties.  Secure  seven  to  ten  pounds  of 
seed  of  each  new  variety,  and  plant,  say,  three  rows  of 
each  on  a  piece  of  land  as  uniform  as  obtainable,  using 
a  standard  variety,  called  A,  as  a  check.  If  we  take 
B,  C,  D,  E  as  four  untried  varieties,  buy  the  seed  jn 
the  fall,  hold  it  all,  including  the  A  seed,  under  simi- 
lar conditions,  and  plant  under  similar  conditions  in  the 
following  order:  A,  B,  C,A,D,  E,  A.  Treat  all  plats 
alike  in  every  respect,  dig  when  ripe,  and  weigh  the 
crop.  If  the  A  plats  yield  approximately  the  same, 
then  the  deduction  is  that  the  soil  conditions  are  fairly 
uniform.  If  not,  compare  the  yield  of  each  plat  with 
the  yield  of  the  A  plat  nearest  to  it.  Condudl  the 
trial  for  three  years.  I  find  that  the  second  and 
third  years'  results  are  better  than  the  first,  as  the 
conditions  are  more  uniform,  although  if  a  variety 
is  a  long  way  ahead  the  first  year  and  shows  up  well 
in  other  ways,  I  would  increase  the  area  under  it  at 
once. 


VARIETIES  87 

Relationship  of  Variety  to  Soil.— Disappointment 
and  loss  are  often  the  result  of  not  knowing  and  study- 
ing the  environment  best  suited  to  a  variety.  Each 
variety,  and  probably  each  individual  in  a  variety  to  a 
lesser  degree,  has  its  idiosyncrasies,  and,  to  succeed, 
these  must  be  recognized  and  catered  to.  The  failures 
in  potato-growing  deserve  more  attention.  The  suc- 
cesses take  care  of  themselves.  The  careful  grower 
takes  note  of  the  failure  and  the  success.  Both  have  a 
cause  or  causes,  and  the  climatology  and  character  of 
the  soil  may  be  among  them.  Some  varieties  do  better 
on  a  heavy  loam  than  on  a  sandy  loam,  probably  be- 
cause the  former  is  cooler,  owing  to  its  greater  moisture 
content,  and  under  such  conditions  these  varieties  give  a 
higher  return  of  starch  per  acre  and  are  of  better  qual- 
ity. Other  varieties,  as  those  inclined  to  be  coarse 
and  rough,  do  better  on  sandy  loams.  In  this  class  are 
Eureka  and  Uncle  Sam. 

Some  require  a  rich  loam  soil — as,  Early  Ohio, 
Bovee,  Early  Harvest,  Early  Michigan.  T.  L.  Wat- 
son,1 of  Virginia,  also  noted  that  some  varieties  want 
more  plant-food  than  others,  other  conditions  being 
the  same.  Others  are  more  cosmopolitan — as,  Car- 
man No.  3,  Early  Rose. 

The  Most  Popular  Varieties. — With  the  obje<5t 
of  ascertaining  the  best  variety  as  determined  by 
yield  in  different  places,  a  letter  was  addressed  to  the 
director  of  each  experiment  station  and  to  some  grow- 
ers; 49  replies  were  received;  28  men  mentioned  vari- 
eties which  had  yielded  or  appeared  to  be  best  in  their 


Va.  Bui.  56,  p.  144. 


88  THE   POTATO 

districts.  In  all  59  varieties  were  mentioned.  Tabu- 
lating the  data  presented,  we  find  that  21  of  these 
varieties  were  mentioned  twice  or  more.  In  the  South- 
ern and  Southern  Trans-Mississippi  States  all  vari- 
eties mature  about  the  same  time  and  may  be  classed 
as  earlies,  and  early  maturing  varieties  are  usually 
planted.  Of  these  and  the  early  varieties,  as  grown  in 
the  North,  Bliss  Triumph  and  Early  Ohio  are  the  most 
popular  with  ten  votes  each;  Six  Weeks  Market  re- 
ceived five;  Early  Rose,  four  ;  Burpee's  Extra  Early 
and  Bovee,  three  each;  while  Beauty  of  Hebron,  Early 
Fortune,  Eureka,  Irish  Cobbler,  Michigan,  and  Polaris 
had  two  each.  Among  late  varieties,  Green  Mountain 
leads  with  eight  votes,  Carman  No.  3  had  five, 
Rural  New  Yorker  and  Sir  Walter  Raleigh  had  four 
each,  and  Burbank,  Carman  No.  i,  Vermont  Gold 
Coin,  Rural  New  Yorker  No.  2,  and  Freeman  had 
two  each.  Although  the  above  method  of  determi- 
nation may  not  be  absolutely  correct,  undoubtedly  the 
varieties  mentioned  are  among  the  favorites. 

Station  Leading  Varieties 

1.  ALABAMA,  Tuskegee     .     Early— Bliss  Triumph. 

Medium — Early  Rose. 
Late — Peerless. 

2.  ALABAMA,  Auburn    .     .     Triumph. 

3.  ARIZONA Burpee's  Extra  Early,  Triumph, 

Early  Rose. 

4.  ARKANSAS Red   Bliss,  Ohio,  Michigan,  Six 

Weeks,  Crown  Jewel. 

5.  CALIFORNIA      ....     Burbank. 

6.  CANADA,  Ontario      .     .     Extra    Early  —  Pinkeye,    Stray 

Beauty,  Early  Ohio. 
Medium— Burpee's  Extra  Early, 

Rose  of  the  North. 
Late— Empire  State,    American 

Wonder. 


VARIETIES  89 

Station        -  Leading  Varieties 

7.  COLORADO  ...     .     .     Medium — Queen  of  the  Valley, 

Rose  Seedling. 
Late— Pearl,  Rural  No.  2. 

8.  CONNECTICUT  ....     Late  —  Green    Mountain,    Car- 

man No.  3,  Rural  New  Yorker. 

9.  ILLINOIS       ....     Early — Early  Ohio. 

10.  IOWA Vermont  Gold  Coin. 

11.  KANSAS Early — Six  Weeks. 

Medium — Early  Ohio. 

12.  G.  L.  Foss, 

Fort  Fairfield,  Me.     .     .     Early— Early  Ohio. 

Medium — Burpee's  Extra  Early. 
Late — Green  Mountain. 

13.  MARYLAND Late — McCormick. 

14.  MASSACHUSETTS   .     .     .     Beauty  of  Hebron,  Early  Rose, 

Early  Andees,  Early  Dawn, 
Triumph,  Salzer's  Earliest, 
I.X.L.,  Steuben,  Early  Nancy, 
Million  Dollar. 

15.  MONTANA Early— Six  Weeks  Market.Early 

Ohio. 
Medium— White    Ohio,      Rural 

New  Yorker. 
Late — Freeman,  White  Main. 

16.  NEBRASKA,  Bui.  80  .     .     Early— Early  Ohio. 

Late — Rural  New  Yorker. 

17.  NEW  HAMPSHIRE      .     .     Late — Green    Mountain,  Wash- 

ington. 

18.  NEW  YORK,  Cornell  .     .     Early — Early  Ohio,  Bovee. 

Late — Green  Mountain,  Carman 
No.  3,  Sir  Walter  Raleigh. 

19.  NEW  YORK,  Geneva      .     Early — Michigan,  Early  Trum- 

bull. 

Late — Carman  No.  3,  Uncle 
Sam,  Whiton's  White  Mam- 
moth, Sir  Walter  Raleigh. 


THE   POTATO 


Station 
iga.   Prof.  STKWART, 

Geneva,  N.  Y. 


20.  LONG  ISLAND,  N.  Y. 

21.  NORTH  CAROLINA    . 


22.  OHIO 


23.  OKLAHOMA  .     .     . 

24.  PENNSYLVANIA 


25.   RHODK  ISLAND  . 


26.  TENNESSEE  .     .     . 

27.  TEXAS,  Bui    71     . 


28.  M.  ALEXANDER, 

Charlotte,  Vt. 


29.  WASHINGTON 


Leading  Varieties 

Rural  New  Yorker  No.  2,  Car- 
man No.  3,  Green  Mountain, 
Sir  Walter  Raleigh.  (Most 
popular  late  varieties  in  the 
State,  apparently.) 

Carman  No.  i,  Green  Mountain. 

Bliss  Triumph  (both  red  and 
white  skinned),  Bovee,  Eu- 
reka, Houlton  Rose,  selected 
strains  of  Early  Rose. 

Late — Green  Mountain,  Wash- 
ington. 

Early  Ohio,  Six  Weeks. 

Medium — Bovee. Early  Fortune. 

Bliss  Triumph,  Early  Ohio. 

Early— Extra  Early  Crusaders, 
Six  Weeks,  Irish  Cobbler, 
Beauty  of  Hebron. 

Medium— J.  A.  Totten,  Free- 
man. 

Early  —  Early  Harvest,  Early 
Fortune,  Polaris. 

Late — New  Queen. 

Triumph. 

Triumph  (generally  grown), 
Thorburn,  Irish  Cobbler,  Eu- 
reka. 

Early— Triumph. 

Medium — Polaris,  Gar  fie  Id, 
Early  Vermont,  Charles 
Downing. 

Late — Green  Mountain,  Dela- 
ware, Alexander's  Prolific, 
Dakota  Red,  Gold  Coin,  Sir 
Walter  Raleigh, Carman  No.  i, 
Carman  No.  2. 
Hurbank. 


^Vv., 


CHAPTER  VIII 
PLANTING 

Distance  Apart. — As  potato  roots  spread  laterally 
to  a  distance  of  2  to  2.5  feet,  the  potatoes  might  be 
planted  in  rows  four  to  five  feet  apart  without  the 
roots  overlapping  in  the  feeding-ground.  The  advan- 
tage of  such  distances  would  be  that  intertillage  could 
be  maintained  until  quite  late  in  the  season,  and  that 
there  would  be  opportunity  to  spray  the  plants  as  late 
as  one  wished.  Whether  such  distances  would  be  eco- 
nomical is  a  local  question  largely  controlled  by  the 
supply  of  moisture  available  for  the  crop.  In  Colo- 
rado the  potatoes  are  usually  planted  in  rows  four  feet 
apart.  In  humid  climates  30  to  36  inches  is  more 
common,  and  27  inches  and  even  less  is  profitable  in 
some  cases.  Other  factors  are  the  value  of  land  and 
the  cost  of  labor.  Where  land  is  low  in  value  and 
labor  high,  wider  rows  and  the  use  of  machinery  are 
necessities.  With  high-priced  land  and  low-priced 
labor  the  rows  may  be  much  closer  together,  and  a 
much  larger  yield  per  acre  may  be  possible. 

The  most  suitable  distance  probably  varies  with  each 
variety;  it  certainly  varies  with  some.  For  spraying 
purposes  a  variety  with  long,  straggling  haulm  requires 
more  space  than  one  with  short,  upright  haulm.  Most 
of  the  early  varieties  belong  to  the  latter  type,  and  such 
are  planted  closely.  Rows  27  to  30  inches  apart,  with 
plants  8  to  12  inches  asunder,  for  early  varieties,  and 

91 


THE   POTATO 


30  to  33  inches,  with  plants  12  to  18  inches  asunder,  for 
late  varieties,  are  suggested  for  most  Eastern  conditions. 
For  irrigation  experiments  in  Wisconsin,  King1  used 
30  x  15  inches  with  success.  In  Europe,  where  heavy 


FIG.    23 — EARLY   MATURING   VARIETIES 

These  generally   have   dwarf    haulm,  and  may  be  planted  much  closer 
together  than  the  later  ones.    This  plant  grew  about  one  foot  tall. 

yields  are  obtained,  the  potatoes  are  planted  close  to- 
gether; thus,  Vuyst,2  of  Belgium,  and  L/avalee3  advise 
that  the  rows  be  24  inches  apart  and  the  plants  12 
inches  asunder,  because  of  the  increased  yield,  the 
hastened  maturity,  and  better- formed  tubers.  West- 
ermeier,4  of  Germany,  states  that  about  360  square 
inches  for  each  plant  gave  the  highest  yield  on  a  humous 


1  "Irrigation  and  Drainage.' 
3  R.  S.  R.,  XII.,  p.  1032. 


K.  H.  King. 


E.  S.  R.,  V.,  p.  232. 
K.  S.  R.,  VII.,  p.  681 


PLANTING  93 

loam.  This  would  result  from  rows  30  inches  apart 
with  plants  12  inches  asunder.  In  the  United  King- 
dom my  observation  is  that  2  7 -inch  rows  with  plants 
1 2  to  15  inches  asunder  for  late  varieties  and  8  to  1 2 
inches  for  early  (Fig.  23)  and  second  early  varieties  is 
most  popular.  The  Maryland  Station1  reports  25  per 
cent,  heavier  yield  from  planting  30  x  14^  inches  than 
from  36  x  12  inches.  The  average  of  Canadian2  exper- 
iments for  the  six  years,  1896-1901,  shows  that  12  to 
14  inches  asunder  in  3o-inch  rows  was  better  than  10, 
1 6,  or  1 8  inches,  whether  considered  from  the  stand- 
point of  total  yield  or  of  total  yield  minus  the  seed.  At 
North  Dakota  Experiment  Station,3  with  4o-inchrows 
and  the  variety  Early  Ohio,  it  was  better  to  plant  the 
sets  10  inches  asunder  than  at  greater  distances. 

Depth  of  Planting. — The  best  depth  varies  to 
some  extent  with  the  soil,  climate,  and  season.  It  is 
better  to  plant  deeper  on  an  open  or  light  soil  than  on 
a  compact  or  clay  soil,  in  order  to  insure  a  more  uniform 
temperature  and  moisture  siipply.  These  conditions 
aid  in  the  production  of  good  quality  tubers.  In  a 
wet  or  a  cold  climate  shallow  planting  may  be  good 
practice.  In  a  wet  season,  on  a  compact  soil,  i  inch 
or  2  inches  deep  seems  to  be  best.  The  Michigan 
Experiment  Station4  reports  that  on  a  sandy  loam,  in 
1892,  the  yields  of  potatoes  planted  at  various  depths 
were,  per  acre  :  2  inches  deep,  275  bushels  ;  3  inches, 
298  bushels ;  4  inches,  279  bushels ;  5  inches,  273 
bushels;  6  inches,  238  bushels.  At  North  Dakota  Ex- 


Md.  Bui.  31,  p.  77.  3  Can.  Exp.  Farms  Report,  1901,  p.  117, 

1  N.  D.  Report,  1901,  p.  96.  *  Mich.  Bui.  95,  p.  9. 


94  THE   POTATO 

periment  Station  3  to  5  inches  deep  gave  the  heavi- 
est yields,  but  5  to  6  inches  deep  is  recommended,  as 
tubers  of  better  quality  are  produced. '  While  in  a  dry 
season,  on  a  rich  clay  loam  soil,  Green2,  of  Minnesota, 
obtained  better  results  from  deep  planting,  the  yields 
being,  per  acre,  planted  on  the  surface,  216  bushels; 
3  inches,  227  bushels ;  6  inches,  297  bushels ;  8 
inches,  328  bushels,  it  was  felt  that  the  results  would 
have  been  different  if  the  season  had  been  wet.  The 
New  Jersey  Experiment  Station3  obtained  similar  re- 
sults, but  found  a  depth  of  4  inches  most  profitable. 
From  the  data  submitted  and  other  sources,  3  inches 
to  4^  inches  seems  to  be  the  most  profitable  depth." 
On  soils  which  are  heavy  and  bake,  and  under  certain 
climatic  conditions,  the  seed  should  be  planted  fairly 
deep,  but  not  covered  more  than  2  inches  or  so,  to  aid 
germination.5  The  soil  can  then  be  gradually  worked 
toward  the  potatoes  until  level  culture  is  obtained. 
This  system  is  sometimes  advocated  for  the  .second 
crop  in  the  South.6 

Influence  of  Depth  of  Planting  on  the  Depth 
at  Which  Tubers  Form. — This  question  is  of  im- 
portance, because  mechanical  diggers  must  be  used, 
and  it  is  essential  to  know  the  depth  to  which  they 
must  work  in  order  to  dig  all  the  crop.  Zavitz,7  of 
Ontario,  as  the  result  of  three  years'  trial,  found  that 
on  an  average  potatoes  from  tubers  planted 


1  N.  D.  Report,  1901,  p.  97.  a  Minn.  Bui.  10,  p.  74. 

3  N.  J.  Bui.  120,  p.  10,  and  Botanist's  Report,  1896,  p.  318. 

*  Ga.  Bui.  29,  p.  304.     Tex.  Bui.  71,  p.  7.        *  Pa.  D.  A.  Report,  1902,  p.  722. 

4  Ga.  Bui.  29,  p.  305.  i  Ont.  Agr.  Coll.  Farms  Report,  1894,  p.  98. 


PLANTING 


95 


One  inch  deep  were  formed  2.3  inches  below  the  surface  ; 
Three  inches  deep  were  formed  2.9  inches  below  the  surface; 
Five  inches  deep  were  formed  4.1  inches  below  the  surface; 
Seven  inches  deep  were  formed  6  inches  below  the  surface. 

It  was  observed  that  those  planted  i  inch  deep  fur- 
nished many  sunburned  potatoes,  while  those  planted 
deeper  had  almost  none.  Gilmore,  of  Cornell,  ob- 
tained somewhat  similar  results  during  the  year  1904. 
Goff,1  of  Wisconsin,  planted  the  Burbank  variety  at 
different  depths,  and  found  that  shallow  planting  in- 
sured greater  germination  and  more  tubers  per  hill,  but 
that  they  were  nearer  the  surface  and  had  more  ex- 
posed tubers. 

TABLE  X 


Depth 
of 
Planting 

Hills  Ger- 
minating 

Tubers 
Protruding 
from 
Soil 

A  veragf. 
Number 
of  Tubers 
per  Hill 

Average 
Weight  of 
Tubers 
Per  Hill 

A  verage 
Depth  to 
Deepest 
Tuber 

Per  cent. 

Per  cent. 

Pounds 

Inches 

2 

100 

8.4 

6.6 

•58 

2-5 

4 

96 

.8 

5-4 

.62 

3-5 

6 

88 

3-2 

•35 

5-o 

The  Canadian  Experiment  Farms"  report,  as  the  re- 
sult of  four  years'  trials,  that  with  tubers  planted  i 
inch  to  8  inches  deep,  where  the  sets  were  planted  less 
than  4  inches  deep,  nearly  all  the  tubers  were  formed 
between  that  depth  and  the  surface,  and  when  plant- 
ed deeper  than  4  inches  most  of  them  formed  within  4 
inches  of  the  surface.  The  deduction  made  from  these 
results  was  that  the  potatoes  developed  in  the  surface 


1  Wis.  Report,  1897,  p.  306,  a  Can.  Exp.  Farms  Report,  1901,  p.  117. 


96  THE  POTATO 

4  inches  of  soil  because  it  was  warmer  than  the  3  or  4 
inches  lower  down. 

Influence  of  Depth  on  Quality. — On  a  sandy  loam, 
under  New  York  conditions,  potatoes  grown  about  4 
inches  deep  are  generally  of  better  quality  than  those 
grown  nearer  the  surface.  In  other  places,  those 
grown  at  even  greater  depths  have  been  observed  to 
be  of  better  quality;  thus,  at  North  Dakota  Station,1 
potatoes  5  to  6  inches  deep  were  better  than  those  3  or 
4  inches  deep  in  this  respect. 

Date  of  Planting. — As  would  be  expected,  the 
dates  of  planting  potatoes  vary  widely,  and  the  only 
way  to  deal  with  the  question  is  to  give  the  common 
dates  for  a  certain  locality.  The  reader  is  advised  to 
inquire  of  the  growers  in  the  locality  the  date  con- 
sidered best,  and,  as  a  general  rule,  it  is  wise  to  plant 
early  for  the  district.  Canadian  experimenters8  report, 
after  four  years'  trial,  that  the  end  of  May  is  the  best 
time,  and  that  June  24  is  usually  found  to  be  the  latest 
date  for  planting  potatoes  to  produce  satisfactory  re- 
turns, although  in  1900  a  good  crop  was  obtained  from 
a  planting  on  July  7.  In  Wisconsin  the  middle  to  the 
end  of  May,  and  in  Maine  late  in  May  and  early  in  June, 
are  considered  best.  At  Cornell  University,  in  1901, 
potatoes  planted  May  16  yielded  250  bushels  per  acre, 
while  those  planted  June  12  and  17  yielded  162  and  197 
bushels  respectively.  In  Oklahoma3  potatoes  planted 
March  14  came  up  and  matured  as  early  as  those 
planted  February  27.  The  early  potato  crop  of  Vir- 
ginia is  usually  planted  during  February  and  March, 


N.  D.  Report,  1901,  p.  96.  *  Can.  Exp  Farm  Report,  1901,  p.  119. 

3  Okla.  Bui.  52,  p.  9. 


PLANTING 


97 


and  the  second  crop  about  August  i.     In  latitude  33° 
the  dates  are  about  two  weeks  later. 

Influence  of  Late  and  Early  Planting. — The 
practice  of  growing  a  late  crop  of  potatoes  has  spread 
northward,  and  in  parts  of  New  York  it  is  custom- 
ary to  plant  potatoes  late  in  the  season  after  another 
crop,  as  peas,  has  been  removed.  The  practice  seems 
commendable,  but  discouraging  reports  from  the  potato 
salesmen  in  regard  to  the  quality  of  these  potatoes  led 
the  Cornell  University  Experiment  Station  to  under- 
take investigations  to  determine,  if  possible,  the  facts. 
Mr.  Gilmore,  who  is  conducting  this  investigation, 
has  furnished  the  first  years'  results,  but  these  are  in- 
sufficient to  permit  of  deductions  being  made. 

TABLE  XI 


VARIETY 

Date  of 
Planting 

Dale  of 
Lifting 

Total 
Mailer 

Ash 
in  Dry 
Malter 

Protein 
in  Dry 

Malter 

Starch 
in  Dry 
Matter 

Green  Mountain.. 
Green  Mountain.. 
Doe's  Fride  
Doe's  Pride  

May  7 
July  6 
May  7 
July  6 

Sept.  ii 

Oct.  22 
Oct.  20 
Oct.  22 

Per  ct. 

& 

21-75 
I9-05 

Per  ct. 

& 

539 

Per.  ct. 

m 

10.35 

I2.II 

Per  ct 

77-38 
72.43 
74.28 
71.14 

In  both  cases  the  late-planted  potatoes  contained 
less  dry  matter  and  less  starch,  or,  in  other  words,  were 
more  watery,  and  appeared  to  be  immature.  Similar 
results  were  obtained  during  the  present  year  (1904). 

Methods  of  Planting. — The  former  method  and 
one  still  quite  common  is  to  plant  potatoes  by  hand. 
A  furrow  is  thrown  out  by  a  common  plow,  or  a 
shovel-plow,  and,  if  applied,  the  fertilizers,  and  in 


PLANTING 


99 


some  cases  the  manure,  are  placed  in  the  furrow,  the 
potatoes  dropped  in,  and  then  covered  by  the  plow. 
Generally  speaking,  the  furrows  should  be  thrown  out 
so  that  the  potatoes  will  be  four  inches  below  ground 
when  the  surface  is  level.  The  furrows  are  made  the 


irtesy  Cornell  University 


FIG.  25 — PLANTING    BY    HAND 

A — Tuber  planted  by  hand  in  furrow  opened  with  a  shovel  or  double  mold- 
board  plow.  B — The  potatoes  covered  with  shovel  plow.  C—  I,aiid  har- 
rowed level  a  few  days  after  planting,  to  destroy  weeds,  leaving  the 
potatoes  four  to  five  inches  deep.  Few  farmers  plant  at  this  depth,  even 
when  they  mean  to  do  so. 

required  distance  apart.  It  has  been  deemed  necessary 
to  place  the  potato  in  position,  and  fix  it  so  that  it  will 
not  move  when  covered.  In  England  this  is  done  by 
requiring  the  planters  to  press  it  down  by  hand,  and 
in  this  country  the  potatoes  are  often  stepped  on  for 
the  same  reason.  The  stepping  on  them  may  injure 


100 


THR   POTATO 


buds,  and  hence  is  detrimental.  The  rows  should  be 
made  straight,  and  care  should  always  be  taken  to 
have  the  potatoes  planted  in  a  straight  line  and  at  a 
uniform  distance  apart.  The  former  facilitates  in- 
tertillage  to  such  an  extent  that  it  is  worthy  of  atten- 
tion. On  a  dry,  hot  day  it  is  inadvisable  to  open  the 


FIG.   26 — SECTIONAL   VIEW    OK   ASI'INWA 


rows  much  ahead  of  the  planters,  and  the  seed  should 
be  covered  as  soon  as  possible  to  prevent  loss  of  mois- 
ture. Frequently  the  rows  plowed  out  before  the  noon 
meal  hour  and  left  open  for  this  time  show  the  injuri- 
ous effecl;  of  the  loss  of  moisture,  especially  if  the  seed 
is  cut.  Wherever  hand-planting  is  done  and  the 
tubers  are  not  sprouted,  the  hand-planters,  which  are 


PLANTING 


101 


somewhat  like  hand  corn-planters,  may  be  used  with 
profit.  They  cost  $i  .00  to  $i  .50,  and  it  is  claimed  that 
an  active  man  can  plant  at  least  one  acre  per  day. 

Every  large  grower  of  potatoes  requires  a  horse- 
planter.  From  six  to  eight  acres  will  warrant  the 
use  of  such  a  machine,  and  it  may  be  made  to  pay  for 
itself  in  a  short  time  by  hiring  it  out — preferably  with 


FIG.   27— ASPINWALI,    POTATO    PLANTER    (SIDE    VIEW) 

a  man  to  work  it.  Some  planters  require  one  man, 
others  two  men,  to  work  them;  the  latter  generally 
do  the  best  work,  although  good  work  is  done  by  the 
former.  Two  systems  of  mechanism  are  employed — the 
picker  and  the  platform.  In  some  planters  the  tubers 
are  fed  from  the  hopper  onto  pickers,  or  spikes,  which 
project  from  a  revolving  vertical  disk.  The  disk 
carries  them  round  to  the  top  of  a  delivery  pipe,  where 
they  are  knocked  off,  or  fall  off,  going  down  the  pipe 


102  THE   POTATO 

to  the  ground.  This  system,  or  a  modification  of  it,  is 
used  in  the  Aspinwall  (Figs.  26-27),  the  Deere,  and  the 
the  Eureka  planters.  Trials  with  a  planter  of  this  type 
showed  that,  with  small  whole  seed  and  well-prepared 
ground,  this  machine  will  work  up  to  its  guarantee  of 
95  per  cent. ;  that  is,  it  will  not  .skip  more  than  5  places 
in  loo.  With  longer  cut  seed  and  rougher  land,  espe- 


FIG.   28 — THE    ROBBINS    IMPROVED    PLANTER 

cially  if  slightly  hilly,  it  will  miss  up  to  20  in  100.  If 
these  misses  were  distributed  it  would  not  be  .so  serious, 
but  often  5  or  6  occur  at  a  stretch.  If  the  seed  is  cut 
long  and  thin,  the  pickers  may  take  hold  of  two  pieces 
instead  of  one.  This  happens  frequently — often  up  to 
20  per  cent.  These  machines  open  the  furrow,  distribute 
the  fertillizer,  plant  the  potato,  and  cover.  The  latter 
operation  is  usually  performed  by  revolving  concave 
disks.  The  distance  apart  of  the  tubers  is  regulated  by 
adding  or  removing  the  pickers.  The  higher-priced 


PLANTING 


103 


machines   are   stronger  made  than  the   lower-priced, 
and,  in  some  cases  the  fertilizer  attachment  is  extra. 

The  Robbins  improved  potato-planter  (Fig.  28)  is  of 
the  platform  type.  The  potatoes  are  elevated  from  the 
hopper  by  means  of  a  wheel,  and  are  discharged  onto  a 
platform  which  is  cleared  by  several  revolving  arms 
(Fig.  29);  the  mechanism  is  so  timed  that  a  potato 


FIG.  29 — THE    PLATFORM    OF    THE    ROBBINS    IMPROVED    PLANTER 

should  fall  on  the  platform  between  each  two  arms. 
Sometimes  the  elevator  comes  up  empty  or  brings  two 
pieces  up  ;  in  either  case  it  is  necessary  for  the  man  sit- 
ting behind  to  put  one  piece  on  the  vacant  part  of  the 
table  between  the  arms  or  take  the  extra  piece  off.  In 
this  way  the  tubers  are  planted  more  carefully  and  regu- 
larly than  most  hand  work.  The  amount  and  distance 
apart  of  seed,  and  the  amount  of  fertilizer  sown,  are 


104 


THE   POTATO 


regulated  by  interchangeable  sprockets.  The  various 
parts  of  the  machine  are  driven  by  means  of  a  chain 
drive.  This  machine  opens  the  row,  distributes  the 
fertilizer  in  rather  a  wide  stream,  plants  the  potato, 
and  covers  it  in  a  satisfactory  manner.  Any  ordinary 
required  depth  can  be  obtained.  It  can  be  used  for 
planting  beans,  corn,  and  other  crops.  With  potato- 
planters  three  to  six  acres  can  be  planted  per  day. 

Losses  of  crop  due  to  insufficient  seeding  cannot  be 
made  up  during  the  year.  The  land  requires  the  same 
amount  of  work,  and  the  soil  needs  moving  at  digging- 
time;  but  there  is  not  the  yield,  and  it  is  an  important 
consideration  whether  5  per  cent,  to  20  per  cent,  loss 
of  plants  per  acre  is  not  too  high  a  price  for  the  sake  of 
one  man's  pay  per  day.  Even  with  the  cheapest 
"  picker ' '  planter,  the  lower  initial  cost  is  not  sufficient 
to  recompense  the  grower  for  the  loss  sustained  by 
using  it  on  ten  acres  when  compared  with  the  'perfect 
machine. 


CHAPTER  IX 
MANAGEMENT   OF    THE    GROWING    CROP 

Cultivation. — Almost  invariably  judicious  cultiva- 
tion of  potato  land  is  profitable.  It  is  secondary  to 
good  preparation  of  the  land.  The  object  is  not 
primarily  to  destroy  weeds,  although  this  may  be  a 
consideration.  To-day  intelligent  farmers  till  to  in- 
crease yield.  Tillage  is  manuring.  No  better  illustra- 
tions of  this  fact  can  be  found  than  the  tillage  experi- 
ments of  Roberts  and  others  at  Cornell  University.1  In 
these  trials  potatoes  were  grown  several  years  in  suc- 
cession, without  manures  or  fertilizers,  upon  the  same 
land,  and  yields  varying  from  300  to  350  bushels  per 
acre,  or  three  to  four  times  the  average  yield  of  the 
State,  were  secured  for  several  years.  This  illustrates 
the  value  of  tillage,  but  in  its  entirety  is  not  necessarily 
a  good  practice.  Tillage  destroys  humus,  and  as  this 
is  one  of  the  most  essential  constituents  of  a  good 
potato  soil,  a  rotation  of  crops  is  advised  to  aid  in 
maintaining  the  supply.  Tillage  may  be  overdone, 
especially  deep  tillage  in  dry  weather.  During  such  a 
time  only  sufficient  shallow  tillage  should  be  given  to 
maintain  a  mulch. 

At  Cornell  from  seven  to  nine  cultivations  seemed  to 
be  most  profitable,  or  about  every  seven  to  ten  days  until 
the  potato-vines  meet  in  the  rows.  Tillage  must  be 
given  when  necessary.  The  right  number  of  cultiva- 


1  (N.  Y.)  Cornell  Bui.  140,  pp.  389-390;  191,  p.  192. 

105 


106  THE   POTATO 

tions  will  vary  with  each  year  and  the  class  of  soil. 
The  Ohio  Experiment  Station1  found  that  thorough 
culture  encouraged  vigorous   growth   and   aided  the 
plants  to  resist  fungous  troubles. 
The  objects  of  tillage,  then,  are  : 

1.  To  increase  the  crop-producing  power,  presum- 
ably by  : 

O)  Liberating  plant-food. 

(£)  Maintaining  good  texture. 

(/)  Conserving  moisture  by  the  aid  of  a  soil  mulch. 

(cf)  Pulverizing  the  ground,  so  that  every  shower 
of  rain  can  enter  the  soil  and  not  flow  off, 
transporting  the  fine  soil  particles. 

2.  To  keep  weeds  in  check. 

System  of  Culture. — Hills. — Generally  hills — that 
is,  where  potatoes  are  planted  in  checks — are  unprofit- 
able because  there  are  not  enough  plants  per  acre  and 
the  yield  is  too  low;  hence  the  system  is  little  used  un- 
less a  piece  of  land  is  very  weedy. 

Drills. — By  "drills"  it  is  understood  that  the  soil  is 
thrown  toward  the  potatoes,  leaving  a  depression  or 
furrow  between  the  rows.  This  system  is  used  for 
irrigation,  when  the  water  flows  between  the  rows.  It 
is  also  practiced  in  humid  climates,  where  the  tempera- 
ture does  not  go  high — as,  Northern  England,  Scot- 
land, etc. — and  on  wet  soils  and  in  wet  seasons.  Often 
the  "furrowing"  injures  roots  and  reduces  the  yield, 
but  many  growers  claim  that  the  ease  with  which  the 
potatoes  can  be  dug  from  drills  compensates  for  any 
loss  in  yield.  The  objection  to  level  culture  is  that 


Ohio  Bui.  76,  p.  47. 


MANAGEMENT  OF  THE  GROWING  CROP    107 

difficulty  is  experienced  in  securing  machinery  which 
will  dig  all  the  tubers. 

Level  Culture.  —  In  this  system  the  potatoes  must  be 
planted  a  little  deeper  than  in  the  case  of  the  other 
two,  to  reduce  the  percentage  of  sun-burned  tubers. 
This  system  is  advocated  throughout  most  of  Eastern 
North  America,  as,  among  other  things,  the  quality  of 


FIG.   30 — HALI.ECK    EXPANSIBLE   WEFDER 

the  potatoes  is  better,  owing  to  the  ground  being 
cooler.  Its  use  has  been  found  advisable  at  such 
various  points  as  Cornell,1  Louisiana, 2  North  Caro- 
lina,3 Wisconsin,4  and  Arkansas6  Experiment  Stations, 
while  the  Maryland8  Station,  in  a  trial  lasting  six  years, 
found  little  difference  between  level  and  drill  culture, 
but  the  slight  variation  was  in  favor  of  level  culture. 

Method  of  Cultivation  and  Tools  Used. — About 
a  week  after  planting  the  spike-tooth  harrow  should 
be  run  over  the  land,  preferably  in  both  directions,  if 
a  mulch  is  not  made  by  one  harrowing.  This  destroys 


1  (N.  Y.)  Cornell  Bui.  140,  p.  390;  156,  p.  175.       2  I<a.  Bui.  22,  p.  705. 

a  N.  Car.  Bui.  85,  p.  4;  146,  p.  262.  *  Wis.  Report,  1899,  p.  210. 

*  Ark.  Bui.  50,  p.  29.  •  Md.  Bui.  62,  p.  204. 


io8 


THE    POTATO 


young  weeds  and  brings  more  seed  up  to  germinate, 
which  may  be  killed  by  another  harrowing  a  week 
later.  When  the  potatoes  appear,  the  weeder  (Fig.  30) 
will  be  found  the  most  serviceable  implement  for  holding 
the  weeds  in  check  and  maintaining  the  mulch.  It  may 


FIG.   31 — FIVK- 


lOTH    CULTIVATOR   WITH    IIILLER    ATTACHMENTS 
vStill  used  by  many  farmers. 


be  driven  across  the  rows  after  each  cultivation  until 
the  potatoes  are  9  or  10  inches  high.  As  a  good 
horse  and  man  can  do  twenty  acres  a  day,  it  is  quite 
expeditious  and  generally  satisfactory. 

Generally  speaking,  it  is  advised  to  cultivate  widely 
and  deeply  from  4  to  6  inches  the  first,  and,  in 
some  cases,  the  second  time  after  the  potatoes  appear, 
then  reduce  the  width  and  the  depth  to  one  inch  or  so. 


MANAGEMENT  OP  THE  GROWING  CROP 


109 


The  first  and  second  cultivations  may  be  given  with  a 
five- tooth  cultivator  (Fig.  31),  or  a  sulky  cultivator 
(Fig.  32)  may  be  used.  The  spring-tooth  cultivator 
(Fig.  33)  is  found  to  be  a  very  useful  tool  for  inter- 


FIG.  32 — A    USEFUL    TWO-HORSE    CULTIVATOR 
A  requisite  wherever  large  areas  of  potatoes  are  grown. 

tillage  work  for  the  third  and  subsequent  cultivations, 
and  the  spike-tooth  expansible  cultivator  with  the 
shields  is  an  excellent  tool  for  shallow  tillage,  as  it 
destroys  the  small  weeds  and  helps  to  maintain  a  soil 
mulch. 


no 


THE  POTATO 


Mulching. — In  some  districts  good  yields  have 
been  obtained  by  mulching  the  land  with  straw, 
shavings,  pine  straw,  or  some  similar  substance,  instead 
of  cultivating  it.  Waugh  found  that  it  increased  the 


FIG.   33 — ONE-HORSE    SPRING-TOOTH    CULTIVATOR 
An  excellent  tool  for  the  later  cultivations. 


yield  in  Oklahoma1  and  similar  results  were  obtained 
in  New  Jersey,2  while  in  Georgia,3  Michigan,4  Wis- 
consin, '"  and  in  my  own  trials  in  New  York,  it  was 
found  to  be  unprofitable,  even  when  the  yields  obtained 
were  about  the  same  under  both  conditions. 


1  Okla.  Bui.  15,  p.  32. 
3  Ga.  Bui.  29,  p.  348. 
8  Wis.  Report,  1899,  p.  209. 


2  N.  J.  Report,  1901,  p.  418. 
*  Mich.  Bui.  95,  pp.  13-16. 


CHAPTER  X 

OBSTRUCTIONS  TO   GROWTH   AND 

DEVELOPMENT 

THE  obstructions  to  growth  may  be  treated  under 
the  following  heads: 

1 .  Season  and  Climate. 

2.  Weeds. 

3.  Diseases  due  to  parasitic  fungi  and  bacteria. 

4.  Insects. 

5.  Arsenical  poisoning. 

i.  Influence  of  Season  and  Climate. — The  in- 
jurious influence  of  dry  weather  at  planting-time  has 
already  been  observed  ("Viability,"  page  66).  At 
the  (Hatch)1  Massachusetts  Experiment  Station  it  was 
observed  that  the  wet  condition  of  the  soil  at  the  time 
of  planting  appeared  to  induce  the  rotting  of  the  young 
plants  just  below  ground.  The  occurrence  of  several 
extremely  hot  sunny  days  in  July,  following  a  long 
rainy  period,  caused  the  plants  to  wilt  from  the  wet 
condition  of  the  soil  and  low  vitality.  No  disease  was 
apparent.  Probably  these  plants  showed  the  injurious 
results  consequent  on  defective  respiration  due  to  high 
temperatures.  Frost  may  cut  down  early  planted 
potatoes. 

Tip  Burn."1 — This  is  most  common  in  Northeastern 


1  Mass.  (Hatch)  Report,  1898,  p.  52. 

o  Ver.  Report,  1899,  p   151;  Bui.  72,  p.  10.    (N.  Y.)  Cornell  Bui.  113,  p.  309 
Conn.  Report  18  (1894),  p.  133. 


112  THE  POTATO 

America.  The  leaves  become  brown  on  the  margin 
and  die.  It  is  caused  by  drought,  and  is  more  prevalent 
on  light  soils.  Irrigation  and  selection  of  vigorous 
varieties,  more  care  in  cultivation,  and  fertilizing  are 
suggested.  At  Wisconsin  Experiment  Station,1  Green 
Mountain,  Rural  New  Yorker  No.  2,  Everett's  Heavy 
Weight,  and  Colossal  proved  most  resistant  in  1896. 

5?^  Scald."1 — Its  effect  is  similar  to  that  of  tip  burn. 
It  is  more  prevalent  in  the  Southeastern  United  States, 
and  is  often  noticed  when  long-continued  damp  weather 
is  followed  by  several  hot,  bright  days. 

2.  Weeds. — These  injure  the  plant  by  using  water 
and  other  plant-food,  crowding  the  plant,  preventing 
the  free  circulation  of  air,  and  in  these  ways  reducing 
the  vitality  and  rendering  the  potato  more  subject  to 
disease. 

3.  Diseases  Due  to  Parasitic  Fungi  and  Bacte- 
ria.— L,ATE  BLIGHT  OR  ROT  3  (Phytophthora  infestans}. 
— There  is  reason  to  believe  that  this  disease  has  existed 
for  ages   in  the  western  parts  of  South  America,  and 
was   disseminated   over  Europe   a   long   time    before 
its  presence  was  recognized.     It  seriously  injured  the 
crops  of  potatoes  in  the  United  States  and   Canada 
in  1843,  alld  reappeared  the  following  year.     In  July, 
1845,  it  was  first  detected  in  Europe,  in  Belgium,  and 
within  two  months  thereafter  it  was  recorded  in  Eng- 
land, Ireland,  Scotland,  France,  Germany,  Denmark, 
and  Russia.     Since  that  time  it  has  never  been  entirely 


1  Wis.  Report,  1896,  p.  240.  =  U.  S.  D.  A.  Farmers'  Bui.  91,  p.  10. 

s  (N.  Y.)  Cornell  Bui.  113,  pp.  297-302.    Vt.  Bui.  49,  pp.  90,  91;  Bui.  72,  p. 
13.    U.  S.  D.  A.  Farmers'  Bui.  91,  p.  8. 


OBSTRUCTIONS   TO   DEVELOPMENT  113 

absent  from  the  potato  crops,  although  in  some  years 
it  is  not  so  destructive  as  in  others. 

The  disease  appears  during  damp,  muggy  weather  in 
August  and  September.  It  is  often  noticed  as  small 
brownish  spots  on  the  lower  leaves,  which  rapidly  en- 
large. In  moist  weather  the  edges  of  these  spots, 
on  the  under  surface  of  the  leaf,  appear  to  be  covered 
with  a  white  downy  mildew.  In  dry  weather  this 
may  be  difficult  to  detect.  Later  the  leaves  appear 
as  though  burnt,  and  finally  the  whole  plant,  and 
in  some  cases  the  whole  field,  will  become  a  putrid, 
offensive  mass  of  decaying  stems  and  leaves.  The 
tubers  may  be  attacked  also,  and  rot  in  the  field  or 
in  storage.  Sometimes  the  disease  runs  a  very  rapid 
course,  and  a  field  will  wilt  down  in  twenty-four 
to  forty-eight  hours. 

Cause. — The  cause  is  a  parasitic  fungus  which  com- 
pletes its  life  history  in  four  or  five  days  or  less.  The 
whitish  mold  is  made  up  of  stalks  bearing  branches 
(Fig.  34).  These  bear  spore  cases  (Figs.  34  and  35), 
which  break  up  to  form  spores  (Fig.  35).  These 
spores  send  out  small  tubes  (Figs.  35,  36,  37),  which 
enter  the  potato  leaf  through  a  stomata,  or  breathing 
pore  (Fig.  37),  or  penetrate  the  cell  wall  (Figs.  36,  37). 
The  tubes  spread  in  the  walls  of  the  leaf  cells  (Fig. 
34)  like  mushroom  spawn  in  a  mushroom  bed,  utiliz- 
ing the  plant-food  which  should  go  to  form  tubers. 
At  intervals  they  send  out  spore-bearing  branches 
through  the  stomata  (Fig.  34),  which  perpetuate  the 
trouble.  Unless  the  tubers  are  well  covered  with  soil, 
the  spores  may  fall  on  the  ground,  and,  reaching  the 
tubers,  transmit  the  disease  to  them. 


THE   POTATO 


FIG.    34 — SECTION    OK    A    POTATO    LEAK 
(After  Marshall  Ward) 

Showing  the  parts  and  the  threads,  or  mycelium,  of  the  blight  or  rot  (Phy- 
tophthora  infestans)  a — Epidermis,  or  outer  cells,  b — Palisade  cells,  which 
aid  in  giving  rigidity  and  firmness  to  the  leaf,  and  in  the  manufacture  of 
starch  and  other  ingredients,  c — Spongy  tissue,  showing  cells  and  large 
air  spaces  between,  d — The  stomata,  or  breathing  pores  of  the  leaf,  with 
aerial  branches  of  the  parasite  growing  outward  through  them,  e — The 
spore  sacs,  or  conidia,  in  which  the  spores,  or  seeds,  are  formed,  f—  A  pe- 
culiar hair  on  the  under  surface  of  the  leaf.  The  dots  in  the  cells  are  the 
chlorophyll  granules,  which  give  the  green  color  to  the  leaf,  and  aid  in  the 
production  of  starch.  The  dark  parts  of  the  tissue  show  where  cells  are 
dying  from  the  effects  of  the  disease.  I,oss  of  cells  means  a  reduction  in 
the  amount  of  food  prepared,  and,  consequently,  reduced  yield.  In  New 
York  alone  the  farmers  lose  $S, 000,000  to  $10,000,000  annually  from  diseases, 
and  because  they  do  not  spray.  This  is  the  most  important  disease  preva- 
lent at  present. 

Aids  to  Attack. — i.  Flea-beetles  puncture  the  leaves 
and  furnish  easy  access  for  the  spores  to  the  inner 
parts  of  the  leaf. 

2.  Humid,  still  days,  with  a  tempera-feure  of  about  73° 


OBSTRUCTIONS   TO   DEVELOPMENT  115 

F.     Above  78°  F.  and  below  50°  F.  there  is  pradlically 
no  germination  of  the  spores. 

Prevention. — i.  Spraying  with  copper  compounds — 
as,  Bordeaux  mixture,  copper  sulphate  and  soda  mix- 


FIG.  35 — THE     MATURATION     OK    A     SPORE    SAC     (CONIDIA)     AND 
GERMINATION     OF    A    SPORE    (ZOOSPORE)    OF     ROT 

(Phytophthora    infestans} 

(After  Marshall  Ward) 

a — Ripe  spore  sac  in  water,  b — The  protoplasmic  contents  break  up  into 
blocks  and  escape  as  kidney-shaped  zoospores  (c  and  rf).  e — Each  have 
two  thread-like  arms,  called  cilia,  which  are  lost  as  the  spore  comes  to  rest 
(/and  g)  ;  k,  i,j\  and  k  show  stages  of  germination.  Moist,  warm,  or  still, 
muggy  days  are  best  for  the  growth  and  development  of  these  spores.  On 
such  occasions  the  disease  spreads  rapidly. 

ture.  If  the  surfaces  of  the  leaves  and  stems  be  covered 
with  a  thin  film  of  some  copper  compound,  we  either 
prevent  the  entrance  or  injure  the  vitality  of  the  ger- 
minating spore  tubes,  so  that  the  potatoes  enjoy  a 
certain  degree  of  immunity  from  the  di.sease. 

This  is  the  philosophy  of  the  use  of  Bordeaux   mix- 


n6 


THE   POTATO 


ture.  The  degree  of  immunity 
varies  with  our  ability  to  keep 
the  whole  of  the  plant  covered 
with  an  armor  of  Bordeaux 
mixture.  Plants  half  sprayed 
are  not  secure,  as  the  disease 
can  spread  rapidly  inside  the 
plant.  The  plant  must  be  com- 
pletely coated  all  the  time  to  be 
immune.  This  may  be  impos- 
sible when  a  plant  is  growing, 
but  this  is  not  the  fault  of  the 
Bordeaux  mixture.  The  more 
thoroughly  and  more  frequently 
the  spraying  is  done  the  better 
the  chances  of  bringing  the 
crop  through.  It  will  be  seen 
that  Bordeaux  is  but  a  prevent- 
ive; it  is  not  a  cure.  Hence, 
the  poor  results  from  spraying 
after  the  disease  has  obtained  a 
foothold. 

2.  Obtaining  disease-resisting 
varieties,  or  changing  the  seed 
if  it  has  lost  its  resisting  power. 

3.  Planting  on  fresh  ground, 
and  planting  early. 

4.  Giving    good    cultivation, 
and  having  a  good  rotation. 

5.  Destroying    all   refuse    of 
potatoes. 

6.  Having  good  drainage — both  water  and  air  drain- 


KIG.  36— LONGITUDINAL 
SECTION  OF  A  POTATO 
STALK,  SHOWING  A  GER- 
MINATING SPORE  OK  ROT 

(Phytophthora  infeslans) 
(After  Marshall  Ward) 

The  number  of  stomata  per 
square  inch  on  a  potato  stem 
is  much  smaller  than  in  the 
case  of  a  leaf,  but  here  the 
germ  tube  has  pierced  the 
cell  wall,  and  is  growing  in 
the  cell.  In  spraying,  the 
stems  should  be  coated  with 
Bordeaux. 


OBSTRUCTIONS   TO   DEVELOPMENT 


1 1 , 


age.  Near  woodland,  where  the  air  drainage  is  poor, 
the  disease  spreads  rapidly  on  damp  or  misty  days. 
Land  choked  with  weeds  keeps  the  lower  leaves  and 
stalks  damp,  and  more  subject  to  attack. 


F'G.   36 — THE    GERMINATING    TUBE    OF    A    SPORE    OF    ROT 

{Phytophthora  infestans) 

(After  Marshall  Ward) 

This  may  enter  a  plant  through  a  stomata,  or  breathing  pore,  as  at  a,  or 
it  may  penetrate  the  cell  wall,  as  at  b.  The  maintenance  of  a  coat  of  Bor- 
deaux mixture  all  over  the  plant  would  check  the  growth  of  these  spores. 


7.  Not  digging  until  ten  da)rs  after  the  vines  die. 

8.  Getting  potatoes  out  of  the  field  as  soon  as  dug, 
and  never  covering  piles  of  potatoes  with  spore-laden 
haulm. 


\  1 8  THE   POTATO 

EARLY  BLIGHT,  '  OR  LEAF  SPOT  DISEASE  (Macro- 
sporium  solani}. — It  is  a  fungus  disease  which  appears 
usually  in  June  to  July,  or  ahead  of  the  late  blight.  It 
does  not  generally  attack  vigorous  plants.  It  spreads 
in  warmer,  drier  weather  than  the  late  blight.  It  forms 
circular  brown  spots  with  target-like  markings  on 
the  leaves.  It  enters  the  leaf  through  tissues  weak- 
ened by  other  agents,  as  flea-beetles,  etc.  It  does  not 
attack  the  tubers  directly,  and  never  causes  them  to  rot. 

Preventives. — i.  Spraying  with  Bordeaux  mixture. 

2.  Selection  of  vigorous  varieties. 

3.  Better  tillage  and  fertilization. 

POTATO  ROSETTE  {Rhizoctonia  solani.*} — This  dis- 
ease has  been  known  since  1842,  but  it  is  only  recently 
that  it  has  caused  considerable  trouble.  It  is  now  well 
established  all  over  the  country,  and  in  some  places  90 
per  cent,  of  the  tubers  appear  to  be  affected  by  it.  It 
tends  to  cause  the  formation  of  an  abnormal  number  of 
small  tubers  of  no  value.  The  stems  show  discolored 
decaying  areas  above  ground  and  brown  dead  areas  be- 
low, and  the  leaves  tend  to  grow  in  rosette-like  clusters. 
The  resting  spores  live  for  several  years  in  the  soil,  and 
the  methods  of  infection  are  by  seed  potatoes,  beet  and 
mangold  roots,  dead  potato  stems,  and  some  weeds; 
hence,  fields  should  be  kept  clean.  The  disease  at- 
tacks beets,  mangolds,  and  clover.  Soaking  the  seed 
in  formalin  will  destroy  the  spores  on  the  potatoes,  but 
is  of  no  value  if  the  soil  is  infected.  Planting  sound 


1  Vt.  Bui.  49,  pp.  91-96;  Bui.  72,  pp  16-25.  U.  S.  D.  A.  Farmers'  Bui.  15,  pp. 
4,  5;  Bui.  91,  p.  5.  (N.  Y.)  Geneva  Bui.  123,  p.  236.  N.  H.  Bui.  45,  pp.  50,  56. 
Tex.  Bui.  42,  p.  923. 

*  (N.  Y.)  Cornell  and  Geneva  Bui.  186.   Col.  Bui.  69,  70.   Ohio  Bui.  139,  145. 


OBSTRUCTIONS  TO   DEVELOPMENT  IIQ 

tubers  and  a  good  rotation  of  crops  will  aid  in  com- 
batting the  trouble. 

SCAB  (Oopsora  scabies  Than.). — Thaxter  has  shown 
that  this  fungus  is  the  chief  cause  of  scab  (Fig.  38), 
although  Roz£  claims  that  the  primary  cause  is  badle- 
rial,  and  that  the  fungus  Oospora  scabies  and  other 
organisms  follow,  causing  the  familiar  rough  and 
cankerous  appearance  of  scab.  Other  causes  are  also 
given.1  An  enormous  amount  of  work  has  been  ex- 
pended on  this  disease,  and  still  no  absolute  preventive 
is  known  if  the  land  is  inoculated  with  the  trouble. 

Treatment. — Of  a  large  number  of  substances  used 
for  treating  the  seed  potatoes,  soaking  them  in  a  solu- 
tion of  formalin,  i  pound  to  30  gallons  of  water,  for  2 
hours  is  the  most  effective.  Soak  the  potatoes  before 
cutting  them,  and  if  they  are  not  planted  at  once 
spread  them  thinly  to  dry.  If  left  in  bags  they  will 
heat  and  the  buds  be  ruined.  After  soaking  two  or  three 
lots  of  potatoes  the  solution  should  be  changed,  as  it 
loses  its  efficacy.  A  big  cheese-vat  or  sheep-dipping 
vat,  in  which  several  bags  may  be  placed  at  a  time,  is 
useful.  A  small  block  and  tackle  will  enable  one  man 
to  lift  large  bags  in  and  out  of  the  vat,  and  suspend 
them  to  permit  of  some  drainage. 

The  following  points  are  of  importance. 

An  acid  condition  of  the  soil  is  injurious  to  the 
growth  of  scab.  Lime,  wood  ashes,  and  barn  manure 
aid  the  growth  of  scab,  while  sulphate  of  ammonia, 
muriate  of  potash,  sulphate  of  potash,  kainit,  acid  phos- 
phate, and  dissolved  bone  render  the  soil  less  favorable 


W.  Va.  Special  Bui.  44,  pp.  285-6. 


2   S 


OBSTRUCTIONS  TO   DEVELOPMENT  121 

to  the  disease.  Scabby  seed  will  inoculate  clean  land. 
Scabby  potatoes  cannot  be  sold.  If  used  as  fertilizer, 
even  after  steaming  for  twenty  minutes1  or  being  ex- 
posed to  the  weather  all  winter,  they  will  inoculate  the 
land  they  are  spread  on. 

Exposing  tubers  to  sunlight  for  four  weeks  before 
planting  reduces  the  percentage  of  scab  and  hastens 
growth. 

Scab  can  live  in  the  soil  at  least  six  years  without  a 
known  host.  Beets,  mangolds,  turnips,  and  rutabagas 
are  subject  to  the  same  disease;  hence  in  the  rotation 
these  crops  should  be  avoided,  if  possible. 

Varieties  vary  in  their  susceptibility  to  scab,2  the 
thicker  skinned  varieties  being  reported  as  most  re- 
sistant. 

It  seems  to  be  useless  to  treat  scabby  seed  if  they  are 
to  be  planted  on  scab-infested  land.3 

Plowing  under  green  rye  does  not  diminish  scab,  as 
has  been  stated." 

Applying  sulphur  in  the  rows  at  the  rate  of  300 
pounds  per  acre  and  more  has  been  tried  extensively, 
but  is  not  recommended  as  a  practice,  as  it  is  of  little 
use  on  infested  land. 

Diseases  in  Storage. — WET  ROT  has  several 
causes. 

i.  Blight  or  Rot  (Phytophthora  infestans).  The 
tissues  of  the  tuber  become  soft  either  partially  or 
wholly,  the  skin  shrinks,  and  the  layer  under  it  be- 
comes pasty.  Potatoes  from  light  soils  appear  to  be 


1  N.  J.  Report,  1899,  pp.  344-345.        2  N.  J.  Report,  1899,  p.  329;  1900,  p.  417. 

3  (N.  Y.)  Geneva  Bui.  138,  p.  631. 

*  (N.  Y.)  Geneva  Bui.  138,  p.  629.    N.  J.  Report,  1900,  p.  417. 


122  THE   POTATO 

less  subject  to  it  than  those  from  heavy  soils,  and  the 
disease  spreads  most  rapidly  in  a  damp,  warm,  and 
close  cellar. 

2.  Due  to  bacteria.1  The  tubers  may  be  wholly  or 
partially  soft,  and  exhale  a  disagreeable  odor.  Butyric 
acid  may  be  liberated  and  the  destruction  of  the  tubers 
is  slow.  Contact  with  other  potatoes  should  be  avoided. 

If  to  be  used  for  seed,  in  some  cases  depending  on 
the  cause,  soaking  the  tubers  in  formalin  before  plant- 
ing is  beneficial. 

DRY  ROT  may  be  the  evidence  of  the  presence  of  one 
or  more  of  several  troubles.' 

1.  Stem  rot,3  bundle  blackening,  dry  end  rot,  is  be- 
lieved to  be  due  to  a  fungus  (Fusarium  oxysporum); 
the  leaves  curl,  and  the  foliage  wilts  and  dies.     The 
tubers  show  brown  or  blackened  bundles  at  the  stem 
end   under   an  apparently  sound   skin.     The   disease 
spreads  rapidly  in  storage,  especially  if  the  rooms  are 
warm.     Some  investigators  advise  that  diseased  tubers 
should  not  be  fed  to  stock,  thrown  on  the  manure-pile, 
or  planted,  and  that  all  such  potatoes  should  be  de- 
stroyed at  harvest-time  or  as  soon  as  discovered.     No 
remedy  is  known. 

2.  Due  to  bacteria.     The  tubers  may  be  free  from 
odor,  moderately  firm,  but  more  or  less  soft  in  spots, 
showing  in  places  a  loose  skin,  which  3  ields  to  the  fin- 
ger, and   under   which  are  white,  gray,  or  brownish 
blotches.     Soaking  unaffected  tubers  in  formalin  before 
planting  is  suggested. 

1  111.  Bui.  40,  p.  140.  a  HI.  Bui  40  p   ,39      Tex.  Bui  42(  p  926 

*  U.  S.  D.  A.  Bureau  of  Plant  Industry  Bui.  55.     (N.  Y.)  Geneva  Bui.  101, 
pp.  83,  84;  Bui.  138,  pp.  632,  634. 


OBSTRUCTIONS  TO   DEVELOPMENT 


I23 


4.  Insects. — THE  FLEA-BEETLE  (Crepidodera  (Epi- 
trix}  cucumeris}  (Fig.  39). — These  small  insects  often 
cause  more  loss  than  the  potato 
beetles.      They    perforate    the 
leaves  (Fig.  40)  during  a  critical 


FIG.   39  —  THE     CUCUMBER 

FLEA-BEETLE  (Crepidodera 
(Epitrix)  cucumeris} 

(After  Chittenden) 
Highly  magnified.    The  insect  j 
is  barely  one-eighth  inch  long.   , 
The  damage  done  by  this  in-  . 
sect    is    considerably    under- 
estimated. 

period  of  the   plant's 
life.     The   holes  pro- 
duced are  used  by  the  FIG  40_LEAFLET  OF  POTATO,  SHOW. 
spores    of    both    early   ING  OVER  A  HUNDRED  HOLES  MADE 


and    late 


for 


BY    FLEA-BEETLES 


blight 

entrance  into  the  leaf.  The  ease  with  which  this  damage  might  be 

....  overlooked  is  evident.    These  holes  make 

Arsenical  poisoning  IS  suitable  avenues  for  the  entrance  of  spores 

USUally      first      noticed  of  disease,  and  pave  the  way  for  the  rapid 

..  destruction  of  the  plant. 

on    the     margins     of 

these  holes.     At  no  time  in  their  life  history  can  these 

insects  be  readily  destroyed.     They  dislike  Bordeaux 


124  THE   POTATO 

mixture ;  hence,  the  only  known  means  of  reducing 
their  ravages  is  to  spray  the  plants  with  this  material. 

NUMBER    OF    FLEA-BEETLE     PUNCTURES     IN     5O     LEAFLETS     FROM 
12    ADJACENT    ROWS  ' 

Punctures 

Row  i. — Sprayed- with  very  weak  Bordeaux  mixture  .  1,794 
Row  2. — Sprayed  with  very  weak  Bordeaux  mixture  and 

soap 1,071 

Row  3. — Not  Sprayed 2,511 

Row  4. — Sprayed  with  strong  Bordeaux  mixture  .  .  1,194 
Row  5. — Sprayed  with  strong  Bordeaux  mixture  and 

soap 1,090 

Row  6. — Sprayed  with  weak  Bordeaux  mixture  .  .  .  1,295 

Row  7. — Sprayed  with  weak  Bordeaux  mixture  and  soap  901 

Row  8. — Not  sprayed 2,287 

The  grubs  of  the  flea-beetle  infest  the  tubers  and 
roots  of  potatoes,  doing  some  damage  and  causing  the 
trouble  known  as  "pimply  potatoes."4 

In  the  Pacific  Coast  the  flea-beetles  {Epitrix  subcri- 
nita,  L,ec.,  and  E.  hirtipennis,  Mels.)  sometimes  reduce 
the  yield  50  per  cent,  by  their  ravages.  As  they  are 
leaf-eaters,  the  foliage  should  be  sprayed  or  dusted  with 
an  arsenical  poison.  One  pound  of  Paris  green  to  150 
gallons  of  water  per  acre  is  suggested,3  but  it  is  better 
to  apply  the  Paris  green  in  Bordeaux  mixture. 

THE  POTATO  BEETLE,  COLORADO  POTATO  BEETLE, 
OR  POTATO  BUG  (Doryphora  decemlineata) . — Until  1850 
this  insedl  was  confined  to  Mexico  and  the  Rockies. 
In  1859  its  eastward  movement  was  noted,  and  it  is 
now  well  distributed.  A  related  species  (D.  juncta) 


1  Vt.  Bui.  72,  pp.  6-9.  i  (N.  Y.)  Geneva  Bui.  113,  pp.  312-317. 

'  Cal.  Bui.  135,  p.  29. 


OBSTRUCTIONS  TO   DEVELOPMENT  125 

retreated  before  its  advance,  and  is  now  more  common 
in  the  South.  In  New  Mexico1  a  parasite  lives  on  the 
eggs  and  larvae.  The  eggs  are  laid  on  the  potato 
leaves,  on  which  the  young  ' '  bugs  ' '  live,  chewing 
holes  in  or  eating  the  whole  of  the  leaf.  The  insects 
are  most  active  about  blossoming-time,  and  do  con- 
siderable damage  if  left  alone. 

Modes  of  Combatting. — The  leaf  should  be  thoroughly 
coated  with  a  poison,  generally  an  arsenical  compound 
being  used.  The  poison  should  be  applied  as  soon  as 
the  "bugs  "  hatch,  because  the  younger  the  "  bugs  " 
the  more  easily  they  are  destroyed.  Various  arsenical 
compounds  are  used — as,  Paris  green,  arsenate  of  lead, 
and  others.  ' '  Bugs ' '  object  to  Bordeaux  mixture, 
hence  in  applying  the  poison  it  is  found  to  be  good 
practice  to  apply  Bordeaux  mixture  at  the  same  time. 
The  whole  of  the  plant  should  be  covered,  because  if 
badly  sprayed  the  bugs  live  on  the  unsprayed  foliage. 
The  standard  application  is  ^  to  ^  pound  of  Paris 
green  to  50  gallons  of  mixture.  Generally  i  pound  of 
Paris  green  is  sufficient  per  acre,  and  if  it  is  desired  to 
apply  more  than  100  gallons,  the  proportion  of  Paris 
green  should  be  varied  accordingly.  If  desired,  Paris 
green  may  be  applied  in  the  dry  form  by  means  of  a 
powder  gun,  the  Paris  green  being  mixed  with  flour, 
land  plaster,  etc.,  as  desired.  About  50  cents  per  acre 
should  cover  the  cost  of  one  application. 

THE  POTATO  WORM,*  also  known  in  the  South  as 
the  tobacco-leaf  miner  (Gelechia  operculella ,  Zell.),  is 
estimated  to  destroy  25  per  cent,  of  the  potato  crop 


1  American  Naturalist,  1899,  pp.  927-29.    New  Mexico  Bui.  33,  pp.  47-51. 
Cal.  Bui.  135,  pp.  5-29. 


126  THE    POTATO 

on  the  Pacific  Coast.  Great  losses  often  occur  in  stor- 
age as  well  as  in  the  field.  The  moths  fly  at  night, 
and  lay  eggs  on  the  stalks  and  tubers.  Destruction  of 
the  moths  by  trap  lanterns,  the  destruction  of  infested 
stems,  careful  hilling  of  potatoes,  getting  them  under 
cover  as  soon  as  dug,  cleaning  up  the  refuse  of 
the  field,  and  a  rotation  of  crops  is  recommended. 
In  storage,  fumigation  with  i^  pounds  of  carbon 
bisulphide  per  thousand  cubic  feet  of  air-space  will 
destroy  all  the  larvae  if  repeated  five  times  at  intervals 
of  two  weeks.  This  gas  is  inflammable,  and  no  lights 
must  be  taken  near.  It  is  a  heavy  gas,  and  sinks  from 
the  top  of  the  building. 

POTATO  STALK  WEEVII,  '  (  Trichobaris  trinotata  ) . — 
This  beetle  attacks  the  stalks,  causing  them  to  wilt. 
It  is  found  from  Canada  to  Texas  and  Florida.  The 
vines  should  be  destroyed  as  soon  as  attacked,  and 
weeds  belonging  to  the  potato  family  kept  down. 

Another  insect  has  caused  similar  trouble  in  Maine.3 

GRASSHOPPERS  {Melanoplus  sp.)  do  much  damage 
during  some  seasons,  especially  after  the  hay  crop  is 
cut,  by  severing  parts  of  the  leaves.  Bordeaux  mix- 
ture containing  an  arsenical  poison  is  the  best  deter- 
rent, being  better  than  the  arsenical  compound  alone. 

THE  JUNE  BUG  (Lachnosterna  sp.). — The  big  white 
larvae  of  these  beetles  often  eat  the  tubers.  They  are 
most  prevalent  on  land  which  has  been  in  grass, 
although  if  land  is  in  clover  but  one  or  two  years  less 
trouble  may  be  expected. 

1  Consult  U.  S.  D.  A.  Div.  of  Entomology,  Bui.  33,  6.    Ind.  Report,  1895. 
Kan.  Bui.  82.    Pa.  D.  A.  Report,  1896.    N.  J.  Bui.  109,  pp.  25-32. 
3  Me.  Report,  1897,  p  173. 


OBSTRUCTIONS   TO   DEVELOPMENT  127 

Wireworms  injure  potatoes  by  boring  through  them. 
They  are  more  prevalent  on  land  which  has  been  in 
grass  a  few  years.  Frequent  rotation  and  fall  plowing 
are  advised  for  both  of  these  pests. 

Other  insects  injurious  to  potatoes  include:  Striped 
Blister  Beetle,  or  ' '  Old-fashioned  Potato  Bug ' '  (Epi- 
cauta  vittata).  This  insect  should  be  combatted  in  the 
same  way  as  the  Colorado  potato  beetle — by  applica- 
tions of  arsenical  poisons  to  the  foliage.  The  Tomato 
Worm  and  Cutworms  are  injurious.  The  latter  are 
very  destructive  at  times,  and  the  best  remedy  seems 
to  be  to  place  bait,  made  of  moist  bran  and  sugar, 
poisoned  with  Paris  green  in  the  fields.1 

Arsenical  Poisoning. — Paris  green,  London  pur- 
ple, and  other  arsenical  compounds  usually  carry  their 
arsenic,  in  an  insoluble  form,  but  some  may  be  soluble. 
This  soluble  arsenious  oxide  may  burn  the  leaves,  espe- 
cially the  tips  where  the  mixture  flows,  and  the  edges 
of  mutilated  leaves,  causing  death  of  the  spot  and  a 
' '  target-like  ' '  appearance  of  the  leaf. 

Remedy. — Do  not  use  more  than  i  pound  of  Paris 
green  per  acre,  dissolved  in  100  to  200  gallons  of  Bor- 
deaux mixture.  The  trouble  is  most  prevalent  where 
people  half  spray  and  use  Paris  green  alone,  or  i 
pound  of  Paris  green  in  one  barrel  (50  gallons)  of 
water  and  lime  or  Bordeaux  mixture. 


1  N.  J.  Bui.  109;  Report,  1895,  p.  366. 


+*J   //,     //^-  /„?*>. 
CHAPTER  XI 

SPRAYS  AND  SPRAYING 

FUNGICIDES  are  materials  used  to  combat  fungi,  or 
small  plants  which  are  usually  parasitic. 

Bordeaux  mixture  is  the  leading  fungicide  for  pota- 
toes. The  ingredients  for  making  this  mixture  are 
freshly  slaked  lime  and  copper  sulphate.  The  fungi- 
cidal  value  lies  in  the  copper  compound.  The  lime  is 
added  to  prevent  the  copper  sulphate  burning  the  foli- 
age, and  to  make  the  mixture  more  adhesive  and  more 
readily  seen  when  applied.  The  amount  of  lime  and 
copper  sulphate  used  vary  considerably.  Not  less  than 
2  pounds  of  lime  can  be  used  to  3  pounds  of  copper 
sulphate.  Excess  of  lime  is  disadvantageous  in  some 
ways,  as  it  renders  the  mixture  less  efficient  by  making 
it  thicker,  and  in  this  way  more  liable  to  settle1  and 
more  difficult  to  apply,  causing  nozzles  to  clog,  but  in 
a  wet  season  an  excess  of  lime  is  desirable.  A  thin 
mixture  can,  however,  be  more  uniformly  applied. 

Use  freshly  burnt,  clean,  firm  lime;  slake  it  by  pour- 
ing water,  preferably  hot,  over  it  in  small  amounts  at 
a  time,  until  the  lime  has  fallen  to  a  fine  powder  ; 
then  add  enough  wrater  to  make  a  thin  paste.  A 
large  quantity  of  lime  may  be  slaked  at  one  time  and 
kept  covered  with  water.  This  is  a  "  stock  solution." 

To  dissolve  copper  sulphate,  it  should  be  placed  in  a 


(N.  Y.)  Ge 
128 


SPRAYS   AND   SPRAYING  1 29 

coarse  sack  and  suspended  in  the  top  of  the  water  in  a 
wood,  brass,  or  porcelain  vessel — usually  a  wooden 
barrel,  as  it  corrodes  iron.  The  copper  sulphate  sinks 
in  the  water  as  it  dissolves,  and  a  gallon  of  water  will 
dissolve  3  pounds  of  copper  sulphate.  This  is  a  satu- 
rated solution.  If  6  pounds  of  copper  sulphate  are  re- 
quired to  a  barrel  of  water,  2  gallons  of  this  stock 
solution  should  be  used. 

Mixing. — It  is  economical  to  have  an  elevated  stage, 
under  or  alongside  of  which  the  spray-cart  may  be 
drawn.  Place  four  so-gallon  barrels  on  this  stage, 
two  of  which  are  for  the  stock  solutions  of  lime  and 
copper  sulphate,  and  two  for  making  the  mixture. 
To  make  50  gallons  of  Bordeaux  mixture,  pour  2  gal- 
lons of  copper  sulphate  saturated  solution  into  one 
barrel  and  fijl  it  up  to  the  25-gallon  mark  with  water. 
Stir  up  the  stock  solution  of  lime  and  dip  out  as  much 
as  is  required;  if  5  pounds,  then  the  solution  equivalent 
to  this  amount;  strain  it,  to  exclude  particles  which 
might  clog  nozzles,  into  the  lime-mixing  barrel,  and 
fill  up  to  the  25-gallon  mark  and  stir.  The  mixing- 
barrels  should  be  provided  with  2-inch  or  3-inch  rubber 
hose,  one  end  of  which  is  attached  in  an  opening  near 
the  bottom  of  the  barrel,  the  other  free.  When  ready, 
put  the  hose  from  each  barrel  into  the  spray-tank,  and 
let  them  empty  and  mix  together.  The  rubber  hose 
should  be  long  enough  so  that  the  free  end  can  be 
turned  over  into  its  barrel  when  not  in  use.  If  desired, 
the  stock-solution  barrels  may  be  placed  above  and 
over  the  mixing-barrels,  so  that  dipping  out  solution 
is  avoided;  it  may  be  run  out  through  a  faucet. 
Convenience  to  a  water-supply  expedites  the  work. 


130  THE   POTATO 

Testing  Bordeaux  Mixture. — In  practice  little 
attention  is  paid  to  the  quantity  of  lime,  except  that 
sufficient  is  added  to  combine  with  all  of  the  copper 
sulphate.  To  determine  when  this  has  taken  place 
the  potassium  ferrocyanide  test  is  made.  Purchase 
ten  cents'  worth  of  potassium  ferrocyanide,  or  yellow 
prussiate  of  potash,  and  dissolve  it  in  water.  Label 
it  ' '  Poison. ' '  Stir  the  Bordeaux  mixture  in  the  spray- 
tank  and  take  out  a  sample  in  a  small  vessel,  to  which 
add  a  drop  of  potassium  ferrocyanide.  If  no  change 
in  color  is  noted  where  it  dropped  there  is  sufficient 
lime,  but  it  is  better  to  add  lime  solution  equivalent  to 
a  pound  of  lime  more.  If  the  drop  changed  the  color 
of  the  solution  reddish  brown  it  shows  that  there  is 
not  enough  lime. 

Strength  of  Solution.  —  For  potatoes,  i  pound 
of  copper  sulphate  to  7  or  8  gallons  of  water  is  com- 
monly used;  that  is  : 

Copper  sulphate  (blue  vitriol),  6  pounds. 

Quicklime  (not  slaked),  4  to  6  pounds. 

Water,  48  to  50  gallons. 

Bordeaux  Dust,1  or  Dry   Bordeaux   Mixture, 

can  be  made  in  two  ways  : 

1 .  Slaking  the  lime  by  pouring  a  strong  solution  of 
copper  sulphate  over  it. 

2.  Mixing  the  strong  copper  sulphate  solution  with 
freshly  slaked  lime  which  has  been  made  into  a  paste, 
then  placing  the  mixture  in  a  bag  and  drying  and  pul- 
verizing it.     The  two  ingredients  must  be  well  mixed 
and  passed  through  a  fine  sieve.     Dry  Bordeaux  is 
offered  for  sale  under  various  names.     Adler's  Bor- 

1  tor  details,  see  Missouri  Bui.  60.    (N.  Y.)  Geneva  Bui.  243,  p.  325. 


SPRAYS    AND   SPRAYING  13] 

deaux  is  reported  to  be  as  efficient  as  newly  mixed, ' 
but  generally  these  preparations  are  much  inferior  to 
the  newly  prepared,  and,  when  applied  drv,  are  less 
effective  than  in  the  wet  form. 

Washing  Soda  and  Copper  Sulphate  Mixture. 
— This  mixture  is  being  used  with  success  in  parts  of 
Europe.  It  does  not  clog  nozzles,  spreads  evenly  over 
the  leaf,  and  is  easily  and  cheaply  prepared.  The 
washing  soda  is  dissolved  in  water,  poured  into  the 
barrel  of  water  and  stirred,  and  the  copper  sulphate 
added  and  stirred.  Various  strengths  are  in  use,  but 
the  most  satisfactory  one  for  American  conditions  has 
yet  to  be  determined.  We  are  trying  4  pounds  of  cop- 
per sulphate,  6  pounds  of  washing  soda,  and  50  gallons 
of  water,  adding  i  pound  of  lime  if  Paris  green  is  used. 
A  little  over  i  pound  of  washing  soda  might  be  suffi- 
cient to  neutralize  the  4  pounds  of  copper  sulphate,  but 
it  is  safer  to  use  more.  In  Ireland  5  pounds  are  used 
and  for  three  successive  years  in  extended  trials  this 
mixture  has  given  better  results  than  Bordeaux  mix- 
ture.2 At  (N.  Y.)  Geneva  Station,  in  1904,  it  was  not 
so  good  as  ordinary  Bordeaux  mixture. 

Spraying  with  Bordeaux  Mixture. — Benefits. — 
Spraying  with  Bordeaux  mixture  influences  the  potato 
crop  in  the  following  ways  : 

1 .  The  structure 3  of  the  leaf  shows  a  slight  increase 

in  thickness  and  in  strength,  and  so  offers  more 
resistance  to  the  growth  of  disease  spores. 

2.  The  chlorophyll,3  or  green  coloring  matter  of  the 

leaf  and  stem,  is  increased. 


1  Me.  Bui.  73,  p.  55.  2  Department  of  Agric.  for  Ireland  leaflet,  14. 

»  Frank  &  Krtiger.    E.  S.  R.,  VI.,  p.  306. 


132  THE   POTATO 

3.  The    transpiration '    of    moisture    is    greater    in 

sprayed  plants.  Food  is  moved  from  the  roots 
to  the  leaves  in  water,  the  food  is  worked  over, 
and  the  water  is  given  off.  The  more  food- 
laden  moisture  passing  through,  the  greater  is 
the  growth. 

4.  The  assimilation '  or  taking  in  of  food  from  the 

air  by  the  leaves  is  much  greater. 

5.  The  duration  '  of  the  leaves  and  vines2  is  greater. 

6.  The  growing  period3  is  extended  (Fig.  41),  insur- 

ing a  heavier  yield.  In  Vermont  blight  often 
appears  in  August,  and  from  then  on  the  pota- 
toes have  grown  50  bushels  a  week  when  the 
foliage  was  preserved. 

7.  The  tuber  production1  is  increased,  due  to  increase 

in  the  size  of  the  tubers4  and  the  number  of 
tubers  per  plant.  Jones  &  Morse,6  of  Vermont, 
show  that  the  average  yield  for  thirteen  years 
(1891  to  1904),  without  spraying,  was  171 
bushels  per  acre,  while  the  sprayed  plats  yielded 
286  bushels  per  acre,  or  an  average  annual  gain 
of  1 15  bushels  per  acre. 

8.  The  dry  matter6  is  increased. 

9.  Starch  formation1  in  the  tuber  is  considerably  in- 

creased.    At  Geneva,  (N.  Y.)  Experiment  Sta- 
tion6 an  increase  of  7  per  cent,  was  obtained. 
10.  Where  there  is  no  disease'  the  yield  may  be  in- 


Frank  &  Krliger.    K  S.  R.,  VI.,  p.  306  a  Vt.  Report,  1899,  p.  156. 

Vt.  Bui.  40,  pp.  26,  27 ;  Report,  1899,  p.  272.    Can.  Exp.  Farms  Report, 

1901,    p     120. 

(N.  Y.)  Geneva  Bui.  221.  «  Vt.  Bui.  106,  p.  231. 

(N.  Y.)  Geneva  Bui.  221. 

E.  S.  R.,  Vol.  IX.,  p.  765.   (N.  Y.)  Geneva  Bui.  123,  p.  234. 


g  I 


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T.I 

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134  THE  POTATO 

creased  by  spraying,  due  to  increased  vigor  of 
the  plants.  At  the  Vermont  Experiment  Sta- 
tion,1 in  1900,  the  yield  was  increased  73  bushels 
per  acre  by  spraying,  although  blight  did  not 
appear  that  year. 

Time  of  Spraying. — Thoughtfulness,  thorough- 
ness, and  timeliness  are  essential  to  success.  A  man 
must  watch  his  crop,  the  season,  and  conditions;  know 
for  what  he  is  spraying,  and  do  it  intelligently  as  well 
as  thoroughly.  In  wet  years  spraying  should  begin 
earlier  than  in  dry.  The  first  spraying  should  be  given 
early  enough  to  ward  off  the  first  attack.  At  Vermont 
Experiment  Station,  in  1900, "  three  applications  were 
most  economical,  but  the  first  one,  that  of  July  26,  was 
the  most  important,  as  half  the  entire  gain  was  due  to 
it;  the  sprayings  on  August  17  and  September  8  were 
of  about  equal  importance.  At  the  same  station,3  in 
1903,  one  timely  spraying  on  August  10  insured  again 
of  124  bushels  per  acre.  Some  growers  who  sprayed 
twice  in  July  secured  little  benefit,  because  by  the  time 
the  blight  appeared,  the  latter  half  of  August,  their 
plants  were  unprotected.  No  rule  can  be  given;  each 
man  must  watch  for  himself.  In  some  districts  it  is 
profitable  to  give  the  first, spraying  when  the  plants  are 
6  inches  tall,  and  repeat  every  ten  to  fourteen  days,  or 
as  conditions  demand. 

Number  of  Sprayings. — At  (N.  Y.)  Geneva  Ex- 
periment Station,4  in  1903,  spraying  potatoes  five  times 
gave  an  increase  of  30  bushels  per  acre  over  three  times, 
and  three  sprayings  increased  the  yield  88  bushels  per 

1  Vt.  Report,  1900,  p.  272.  «  Vt.  Report,  1900,  p.  273. 

*  Vt.  Bui.  106,  p.  231.  «  (N.  Y.)  Geneva  Bui.  241,  p.  262. 


SPRAYS   AND   SPRAYING  135 

acre  over  no  spraying.  At  Cornell  Experiment  Sta- 
tion '  one  application  of  Bordeaux  mixture,  and  three 
of  Bordeaux  mixture  and  Paris  green,  increased  the 
yield  103  bushels  per  acre,  while  another"  year  six 
sprayings  increased  the  yield  48  bushels  per  acre. 
At  Vermont  Experiment  Station3  two  applications 
have  in  general  proved  most  profitable.  The  (N.  Y. ) 
Geneva  Experiment  Station  recommend,  as  the  re- 
sult of  their  trials  to  the  year  1904,  that  spraying  com- 
mence when  the  plants  are  6  to  8  inches  tall  and 
thorough  applications  to  be  made  at  intervals  of  ten  to 
fourteen  days  during  the  season,  making  five  to  seven 
applications  in  all. 

Insecticides  are  materials  used  to  destroy  injurious 
insects.  Poison  is  spread  on  the  leaves  to  destroy 
leaf-eating  insects,  and  materials  that  kill  by  contact 
are  used  against  insects  that  suck  plant-juices.  For 
poisoning  the  first  class  there  are  on  the  market  a 
number  of  preparations,  which  may  be  grouped  as 
follows:4 

1.  Standard  Remedies. — Scheele's  Green,  Paris  Green, 

London  Purple,  Hellebore. 

2.  Commercial  Substitutes. — Paragrene,   Green  Arsen- 

oid,    Green   Arsenite,    Pink    Arsenoid,    Laurel 
Green,  Arsenate  of  Lead,  Disparene. 

3.  Home-made  Remedies. — Arsenite  of  Lime,  Arsenite 

of  Soda,  Arsenate  of  Lead,  Arseuite  of  Lead. 

4.  Proprietary  Remedies. — Bug  Death,6  Black  Death,6 

Hammond's  Slug  Shot,5  Quick  Death,  Knobug, 


1  (N.  Y.)  Cornell  Bui.  140,  p.  402.    «  (N.  Y.)  Cornell  Bui.  196,  p.  48. 

»  Vt  Bui.  106.  p.  230.  *  From  (N.  Y.)  Geneva  Bui.  243,  p.  329. 

s  For  analysis,  see  (N.  Y.)  Geneva  Bui.  190,  p.  289. 


136  THE   POTATO 

etc.     In  most  of  these  the  amounts  of  arsenical 
compounds  present  is  small. 

Contaft  Remedies — Standard. — Whale  Oil  Soap,   Car- 
bon Bisulphide,  etc. 

While  some  of  the  poisons  in  Group  4  (proprietary) 
have  value,  they  are  too  expensive,  and  the  work  of 
various  experiment  stations  shows  that  Paris  green  or 
arsenate  of  lead  are  cheaper  and  generally  much 
more  effective  poisons.1 

Paris  green  rarely  occurs  on  the  market  pure.  In 
New  York  the  law  requires  that  it  contain  50  per  cent, 
of  arsenious  oxide  or  white  arsenic.  Often  some  of 
this  arsenic  is  soluble  in  water,  and  in  such  cases  it  is 
liable  to  burn  foliage.  If  more  than  4  per  cent,  of 
water  soluble  arsenic  is  present  the  sample  should  be 
condemned. 

Paris  green  tends  to  sink  to  the  bottom  of  the  spray- 
barrel;  hence,  unless  kept  well  stirred,  the  concen- 
trated solution  applied  at  the  last  may  burn  the  foliage. 
It  should  be  applied  at  the  rate  of  about  i  pound  per 
acre,  in  not  less  than  100  gallons  of  Bordeaux  mixture. 
When  applied  dry,  mix  i  pound  of  Paris  green  with 
50  pounds  of  land  plaster,  flour,  slaked  lime,  or  any 
other  dry  powder. 

At  (N.  Y.)  Geneva  Experiment  Station,  in  1904, 
Paris  green  was  applied  to  potatoes  at  the  rate  of  3 
pounds  per  acre  in  1 50  gallons  of  water.  Four  appli- 
cations were  made  during  the  season,  and  no  injury  to 
the  foliage  occurred.  The  results  show  that  Paris 
green  is  of  distinct  fungicidal  value,  and  that  it  in- 


Me.  Bui.  68,  87,  98. 


SPRAYS   AND    SPRAYING  137 

creased  the  yield  of  potatoes  from  175  bushels  per  acre, 
on  plats  where  bugs  were  removed  by  hand,  to  221 
bushels  per  acre,  and  that  it  was  better  applied  in 
water  than  in  lime  water. 

Lead  Compounds. — Insoluble  arsenate  and  arsen- 
ite  of  lead  are  recommended  because  they  contain  no 
injurious  soluble  arsenic,  a  heavy  dose  will  do  no 
harm,  they  lead  all  other  materials  in  remaining  in 
suspension,  they  adhere  to  the  foliage,  and  they  can 
be  easily  made  at  home  and  their  purity  insured.  The 
articles  required  are  sugar  of  lead  (acetate  of  lead), 
costing  7^  cents  per  pound,  wholesale,  and  arsenate 
of  soda,  costing  5  cents  per  pound,  wholesale,  at  pres- 
ent. They  may  be  dissolved  in  cold  water,  but  for 
quick  solution  hot  water  is  better.  The  formula  for 
making  i  pound  of  arsenate  of  lead — enough  for  100 
gallons — is: 

Dissolve  24  ounces  of  sugar  of  lead  in  i  gallon  of 
cold  water,  and  10  ounces  of  arsenate  of  soda  in  3 
quarts  of  water,  both  in  wooden  vessels.1  When  dis- 
solved, pour  together  into  the  spraying-tank.  Pre- 
pared in  this  way,  it  is  superior  to  any  ready  prepared 
sample.  Of  the  latter  there  are  several  makes,  which 
may  be  used  if  but  a  small  amount  is  required.  ' '  Swift's 
Arsenate  of  Lead ' '  may  be  purchased  in  a  white 
powder  form  or  as  a  paste;  it  is  easily  mixed  with 
wrater,  but  both  forms  settle  more  quickly  in  the  spray- 
tank  than  the  freshly  made.  Disparene  retails  at  25 
cents  per  pound,  and  is  a  heavy  white  paste  which 
finally  mixes  well  with  water,  but  takes  some  time. 


»  Cal.  Bui.  151.    (N.  Y.)  Geneva  Bui.  243. 


138  THE   POTATO 

It  has  great  adhesive  power,  and  will  not  burn  foliage. 
The  Adler  lead  compounds  are  similar. 

Arsenite  of  lead  is  made  by  dissolving  separately  12 
ounces  of  sodium  arsenite  and  4  pounds  of  sugar  of 
lead,  then  pouring  them  into  150  gallons  of  water. 
The  home-made  mixture  remains  in  suspension  longer 
than  the  prepared.  Pink  arsenoid  is  arsenite  of  lead 
colored;  it  is  no  more  dangerous  to  foliage  than  Paris 
green,  and  is  cheap.  It  will  remain  in  suspension  about 
twice  as  long  as  Paris  green. 

Green  arsenoid  (copper  arsenite)  sometimes  con- 
tains considerable  soluble  white  arsenic,  and  is  then 
dangerous  to  foliage,  especially  in  a  dry  climate  or 
time. 

White  arsenoid  (barium  arsenite)  is  dangerous  to 
foliage. 

Calco  green  and  laurel  green  do  not  contain  enough 
arsenic  to  render  them  of  much  value,  and  some  sam- 
ples cause  serious  injury  to  foliage.1 

Paragrene  is  a  prepared  compound  containing,  in 
some  cases,  considerable  soluble  ' '  white  arsenic, ' '  which 
is  objectionable. 

Arsenic  and  lime  is  a  cheap  mixture.  Boil  i  pound 
of  white  arsenic,  costing  7  cents  per  pound,  with  2 
pounds  of  lime  in  2  gallons  of  water  for  forty  minutes 
and  add  to  150  or  200  gallons  of  water.  It  cannot  be 
safely  applied  alone,  even  with  the  addition  of  consid- 
erable lime,  but  may  be  used  in  Bordeaux  mixture. 
The  copper  sulphate  in  the  Bordeaux  mixture  seems 
to  prevent  the  caustic  action.  If  the  lime  and  arsenic 
fail  to  combine,  the  mixture  is  dangerous. 

1  Vt.  Report,  1899,  p.  271.    Cal.  Bui.  151,  p.  24. 


SPRAYS   AND   SPRAYING  139 

Cost  of  Spraying  and  Profits  Derived. — In  1903, 
at  the  farm  of  J.  V.  Salisbury  &  Son,  Phelps,  N.  Y., 
the  total  expense  of  spraying1  1 4  acres  five  times  was 
$55.76,  the  items  being  as  follows: 

504  pounds  of  copper  sulphate,  at  6  cents  .  .  $30.24 

8  bushels  of  lime,  at  35  cents 2.80 

12  pounds  of  white  arsenic,  at  5>£  cents  .  .  .66 

55  hours'  labor  for  man,  at  I7/^  cents  .  .  9-63 

47  hours'  labor  for  team,  at  17)^  cents  .  .  8.23 

Wear  of  sprayer        4.20 

$55.76 

Cost  of  spraying  per  acre  for  each  application  was 
80  cents. 

Bushels 

Yield  of  sprayed  rows,  per  acre 147 

Yield  of  unsprayed  rows,  per  acre   .   '»     .   '.       83 

Increase  in  yield  per  acre    .......       64 

A  good  showing,  considering  that  there  was  no  blight 
this  year. 

64  bushels  per  acre  on  14  acres  (896  bushels),  worth  .     $448.00 
Less  cost  of  spraying 55.76 

Net  profit  on  14  acres $392.24 

Net  profit  per  acre 28.01 

Mr.  Salisbury  sprayed  potatoes  for  his  neighbors  at 
80  cents  per  acre  and  furnished  everything.  In  other 
experiments  conducted  in  1 904  by  the  Geneva  Experi- 
ment Station,  the  cost  of  each  application  was  as  low 
as  6 1  cents  per  acre,  and  the  net  profit  as  high  as 
$60.00  per  acre. 


(N.  Y.)  Geneva  Bui.  241,  p.  275. 


140 

Spraying  Machines.1 — A  spraying  outfit  consists 
of  a  pump,  nozzle,  agitator,  tank  rods,  hose,  crop-spray- 
ing attachments,  etc.  They  are  made  in  various  sizes, 
and  are  known  as  knapsack,  carried  and  worked  by  a 
man;  barrel,  hauled  by  man  or  horse  (Fig.  42),  and 
worked  by  manual  labor;  and  power  sprayers,  in  which 
the  pumping  is  done  by  gearing  from  the  wheels,  steam 


FIG.   42— A    SUGGESTIVE    ENGLISH    SPRAYING    MACHINE 
hmphasis  is  laid  upon  coating  the  under  surface  of  the  leaves,  and  experi- 
ments show  that  it  is  profitable  to  do  so  under  British  conditions. 

or  gas  engines,  compressed  air  or  carbon  dioxid.  The 
pressure  is  generated  in  the  pump;  100  to  120  pounds 
pressure  per  square  inch  gives  a  much  finer  spray  than 
50  to  60  pounds.  The  power  sprayers  give  the  former, 
the  manual  labor  sprayers  rarely  exceed  the  latter. 
The  working  parts  of  the  pump  should  be  of  brass  or 
bronze;  rubber  or  leather  valves,  or  any  parts  that  Bor- 


1  Consult  Mo.  Bui.  50  and  (N.Y.)  Geneva  Bui.  243. 


SPRAYS    AND    SPRAYING  14! 

deaux  mixture  will  corrode,  are  inadmissible.  The 
pump  should  be  easy  to  clean. 

The  nozzle  and  the  pressure  determine  the  character 
of  the  spray.  The  Vermorel  type  of  nozzle  is  one  of 
the  best;  it  does  good  work  at  a  low  pressure  of  50  to 
60  pounds,  but  better  work  at  100  pounds.  It  does 
not  throw  the  spray  a  great  distance.  The  nozzle  used 
should  permit  of  being  readily  cleaned. 

The  agitator  may  be  (i)  mechanical  or  (2)  the  jet 
type.  The  former  is  generally  used  and  considered 
more  efficient,  dashers  being  used  in  barrel  outfits  and 
whirling  paddles  in  large  tanks.  The  jet  type  returns 
a  stream  of  solution  from  the  pump  to  the  bottom  of 
the  tank.  It  can  be  made  efficient  on  power  sprayers, 
but  deficiency  of  power  bars  their  use  on  hand  outfits. 

Tanks. — Cypress,  pine,  and  cedar  are  used  in  mak- 
ing tanks,  the  first  being  considered  best.  Their  ca- 
pacity varies  from  50  to  250  gallons. 

Hose. — The  hose  should  withstand  a  pressure  of  125 
pounds  per  square  inch.  Three  and  four  ply  are  most 
used.  Some  prefer  five  and  six  ply.  Half-inch  hose  is 
most  commonly  used;  some  prefer  three-eighths  of  an 
inch . 

Crop-spraying  Attachments. — The  potato  spraying 
attachment  should  carry  two  or  more  nozzles  for  each 
row.  These  should  be  capable  of  being  turned  up- 
ward when  not  in  use,  to  prevent  their  clogging  with 
sediment  while  drying.  The  spray  should  be  thrown 
upward  and  sideways,  to  coat  the  under  surface  of  the 
leaves  as  well  as  the  upper  surface.  From  two  to  six 
rows  are  sprayed  at  a  time  (see  Frontispiece  and  Fig. 
42),  and  the  attachment  should  fold  or  turn  up  to 


142  THE   POTATO 

facilitate  turning  or  going  through  a  gateway.  Sta- 
tionary nozzles  cannot  direct  the  spray  so  well  as  hand 
nozzles;  hence,  more  should  be  put  on  to  make  sure 
that  the  plants  are  coated.  The  cost  of  the  extra 
amount  of  mixture  is  small  compared  with  the  cost  of 
the  labor  used  in  applying  it. 


'•'  f- 


CHAPTER   XII 
HARVESTING 

Digging.  —  Early  potatoes  may  be  dug  as  soon  as 
large  enough.  For  late  varieties  which  are  to  be 
stored  it  is  necessary  to  wait  until  the  tubers  have  at- 
tained full  size,  the  haulm  and  leaves  have  died,  the 
tubers  come  freely  from  the  stem  and  have  not  to  be 
jerked  off,  and  the  skins  are  firm  and  will  not  come 
off  easily  when  rubbed.  If  the  vines  have  been  de- 
stroyed by  blight  the  potatoes  should  not  be  dug  until 
at  least  ten  days  after  the  vines  are  dead,  as  there  is 
then  less  liability  of  rot  in  storage.1  If  frost  sets  in 
early  and  the  growing  season  has  been  late,  it  may  be 
necessary  to  dig  before  the  potatoes  are  quite  mature. 
In  this  case  the  shrinkage  in  weight,  if  stored,  will  be 
greater  than  if  they  had  matured,  and  a  reasonable  offer 
for  them  straight  from  the  field  should  not  be  declined. 
For  storage,  potatoes  must  be  dug  when  dry,  picked 
up  at  once,  and  kept  cool.  If  possible,  haul  to  some 
cool  place  at  once,  and  let  them  cool  all  night  before 
placing  in  storage.  This  is  impossible  where  large 
quantities  are  grown,  and  in  such  cases  good  ventila- 
tion of  the  storage-place  must  be  given  to  reduce  tho 
temperature  as  quickly  as  possible. 

Methods  of  Digging.  —  i.  By  Fork,  .S/W^,  or 
Potato-hook,  —  The  early  potatoes  are  often  dug  by 
hand  because  they  are  so  easily  injured.  The  skin  is 


Vt.  Bui.  106,  p.  233. 

143 


144  THE  POTATO 

tender,  the  tubers  adhere  to  the  stem,  and  often  require 
removal.  It  is  a  slow,  tedious  process,  but  nearly 
every  potato  is  obtained.  A  man  will  dig  one-eighth 
to  three-eighths  of  an  acre  a  day.  With  the  main  crop 
a  man  will  dig  from  one-tenth  to  one-half  acre  a  day  at 
a  cost  generally  varying  between  two  and  six  cents 
per  bushel,  sometimes  running  to  eight  and  occasion- 
ally lower  than  two  cents,  depending  a  great  deal  on 
the  skill  of  the  man,  the  yield,  the  soil,  and  state  of  the 
land.  As  weather  conditions  may  retard  digging,  and 
labor  is  hard  to  obtain,  this  method  is  being  discon- 
tinued except  on  small  patches. 

2.  Plow. — Plowing  out  with  a  common  plow,  or  a 
potato  plow,  or  so-called  "digger,"   many  of  which 
are : 

Modified  Shovel  Plows. — All  that  I  have  tested  have 
been  failures.  They  dig  some  of  the  potatoes  out  and 
cover  some  up.  On  harrowing  after  them  many  more 
potatoes  appear,  and  on  digging  the  rows  some  may 
still  be  found.  My  experience  has  been  that  the  pota- 
toes left  in  would  more  than  pay  for  digging  by  hand. 
They  may  be  useful  for  small  growers  on  a  light  soil, 
and  for  those  who,  being  short  of  labor,  wish  to  save 
part  of  their  crop.  Six  to  ten  hands  and  two  horses 
will  dig  one  and  a  half  to  two  acres  per  day.  In  the 
Southern  States  early  potatoes  are  plowed  out,  and 
ten  cents  per  barrel  is  paid  for  picking  them  up. 

3.  Mechanical   Diggers. —  The    high-priced    horse- 
power  diggers,    as    the    "Reuther"    (Fig.    43),    the 
"Hoover"  (Fig.  44),  and  the  "Dowden,"  are  all  re- 
ported as  satisfactory  machines.     They  work  on  the 
same  principle.     The  shovel-point  is  forced  under  the 


HARVESTING 


145 


row  of  potatoes,  and  the  row  lifted  and  deposited  on 
the  elevator,  which  gradually  shakes  out  the  soil  and 
leaves  the  potatoes  in  a  row  on  the  ground  in  the  rear. 
These  require  two  to  four  horses,  according  to  con- 
ditions, and  do  better  work  on  soils  free  from  stones. 
The  Standard  Digger  is  different.  A  divided  shovel 


FIG.  43 — THE    REUTHER    POTATO    DIGGER 

lifts  the  row  onto  a  shaker,  which  separates  the  pota- 
toes and  soil,  leaving  the  latter  on  the  surface  behind. 
This  digger  works  well  when  potatoes  are  ridged  or 
planted  shallow,  but  when  deep  it  does  not  do  so  well.1 
One  other  form  used  successfully  in  Canada  and  Great 
Britain  consists  of  a  strong  frame  on  two  wheels  and 
a  small  wheel  in  the  front  and  rear.  It  carries  a  set  of 
revolving  forks  working  at  right  angles  to  the  share, 


Minu.  Bui.  52,  p.  439. 


146  THE  POTATO 

which  pass  underneath  the  row  and  raise  it.  The 
forks  throw  the  potatoes  and  soil  against  a  screen, 
which  lets  the  soil  through  but  deposits  the  potatoes 


FIG.   44 — THE    HOOVER    1JUJGER 

in  a  row.     Several  good  diggers  are  made  on  this  plan. 
Two  or  three  horses  are  used. 

With  a  mechanical  digger,  four  to  six  acres  can  be 
dug  per  day,  and  eight  to  sixteen  hands  are  required 
to  pick  up.  The  cost  of  digging  should  not  exceed  two 
cents  per  bushel,  and  may  be  much  less.  Another  ad- 
vantage of  a  digger  is  that  if  the  land  is  clean  it  needs 
harrowing  only  to  be  in  excellent  shape  for  seeding  to 
wheat. 


CHAPTER  XIII 
STORING 

POTATOES  may  be  stored  in  the  open  in  piles  covered 
with  straw  and  earth,  in  cellars  or  root-houses,  accord- 
ing to  the  climatic  conditions. 

Piles. — These  are  useful  for  temporary  storage  in 
the  North.  Dig  a  trench  about  3  or  4  inches  deep,  3 
feet  wide,  and  as  long  as  desired;  make  the  bottom  per- 


FIG.  45 — POTATO    SHOVEL 

feclly  level  and  firm,  so  that  a  potato  shovel  (Fig.  45) 
may  be  used  on  it  when  moving  the  potatoes.  Throw 
the  soil  from  the  trench  onto  each  side,  making  a  bank 
about  1 5  inches  wide  with  it.  This  will  give  a  trough 
about  7  inches  deep  in  which  to  empty  the  potatoes. 
Pile  the  potatoes  neatly,  so  that  the  face  of  the  pile  at 
the  center  will  be  3  feet  or  so  high.  When  sufficient 
potatoes  are  stored,  place  about  3  inches  thick  of  rye  or 
wheat  .straw  (oat  straw  being  liable  to  heat  and  become 
mouldy)  with  the  butts  down  and  heads  up  on  the 
sides  and  one  end  of  the  pile,  leaving  the  other  end 
for  additional  potatoes  (  Fig.  46) .  Then  cover  the  straw 

147 


148 


THE  POTATO 


with  soil,  beginning  at  the  bottom  and  piling  it  toward 
the  apex;  2  or  3  inches  thick  will  be  sufficient  near 
the  top  with  the  straw,  and  6  or  7  inches  at  the  base. 
Finish  the  surface  off  by  patting  it  with  the  spade  so 


FIG.  46 — STORING   POTATOES   IN    PITS 
Useful  in  climates  where  the  winter  is  not  severe. 

that  it  will  turn  rain.  Dig  a  channel  all  around  the 
pile,  using  this  soil  for  the  covering.  The  bottom  of 
this  channel  should  be  below  the  floor  of  the  pile,  and 
have  an  outlet  to  let  off  water,  thus  insuring  a  dry  bot 
torn  for  the  pile.  Leave  the  ridge  of  the  pile  open  to 
permit  the  moisture  to  escape  when  the  potatoes 
"  sweat."  If  it  is  desired  to  hold  the  potatoes  in  these 


STORING  149 

piles  over  winter,  more  soil  or  old  hay  must  be  put 
over  them  as  the  frost  comes  on.  The  mouth  of  the 
pile  should  be  closed  at  night,  and  care  should  be  taken 
to  have  no  potatoes  left  on  the  ground  at  night.  Rain 
or  frost  may  come  on  and  injure  them,  or  retard  the 
work.  Sufficient  covering  must  be  put  on  the  piles  to 
prevent  the  rain  and  sun  discoloring  the  potatoes.  I 
have  known  a  whole  crop  ruined  by  inattention  to  this 
point.  The  rain  browns  them,  and  the  sun  makes  them 
green  and  unsalable.  This  method  is  not  advisable  in 
the  Northern  States  unless  one  is  sure  that  they  will 
not  want  to  sell  or  put  up  the  potatoes  until  spring,  as 
the  pit  cannot  be  opened  during  frost  or  in  wet 
weather,  and  in  spring  moving  potatoes  on  wet  land  is 
objectionable. 

Cellars. — If  seed  potatoes  only  are  held,  they  may 
be  kept  in  trays,  bushel  boxes,  or  barrels,  storing 
these  so  that  air  can  circulate  under  and  round  them, 
or  they  may  be  held  in  bins. 

Construction. — The  location  of  the  cellar  should 
be  dry  and  well  drained.  It  should  be  built  under- 
ground, of  concrete,  brick,  or  stone  walls,  with  a 
plastered  ceiling  if  a  building  is  above  it,  to  make  a 
dead  air-space  between  the  plaster  and  the  floor.  Con- 
crete walls  are  readily  made  with  clean  gravel,  sand, 
and  cement,  with  boards  to  hold  the  material  while  set- 
tling. Use  one  part  of  Portland  cement,  three  of  sand, 
and  six  of  gravel;  mix  the  sand  and  cement,  then  add 
the  gravel;  wet  and  mix,  and  fill  into  the  wall-space. 
To  hold  it  in  position  while  drying  it  is  customary  to 
use  i -inch  boards,  nailed  onto  2  x  4-inch  studding, 
which  may  be  placed  i  foot  6  inches  on  centers.  To  pre- 


150  THK  POTATO 

vent  sagging,  the  studding  of  one  side  is  braced  to  that 
on  the  other  side  by  ^  x  ^5 -inch  iron  strips,  which 
are  placed  three  feet  apart  each  way,  and  nailed  to  the 
studding  on  each  side.  These  are  left  in  the  wall,  and 
the  ends  cut  off  when  the  boards  are  taken  down. 
Apertures  through  which  to  shoot  the  potatoes  should 
be  left  at  intervals.  One  satisfactory  cellar  of  which  I 
know  has  a  driveway  through  the  center  and  bins  on 
each  side.  The  bins  are  about  10  feet  wide  and  are 
filled  4  to  6  feet  deep.  Divisions  are  put  in  as  desired. 

Ventilation  and  Temperature  are  most  impor- 
tant. The  potatoes  must  be  kept  cool,  about  33°  F. 
being  a  favorable  temperature.  If  possible,  lead  air 
through  a  deep  underground  drain-tile  into  the  cellar; 
the  length  of  the  tile  should  be  sufficient  to  warm  the 
air  a  little  in  winter,  and  the  outside  end  of  it  should 
be  covered  to  prevent  the  entrance  of  vermin.  A 
ventilator  on  the  roof  will  remove  warm  air.  Have  a 
raised  board  floor  in  each  bin  and  a  ventilator  running 
from  it  up  through  the  tubers  at  intervals.  Have 
double  doors  at  the  entrance  and  the  shoots,  and  keep 
the  place  dark.  Darken  the  windows  if  there  are  any. 
A  small  cellar  can  be  made  if  desired,  but  make  the 
roof  high  enough  to  work  in — say,  8  feet.  Purchase  a 
reliable  thermometer  and  hang  itvin  the  cellar,  an  oil- 
stove  and  radiator,  and,  if  the  temperature  is  going 
down  too  low,  warm  the  place.  It  is  folly  to  have 
potatoes  freeze  to  save  ten  cents  worth  of  kerosene. 

The  advantages  of  a  cellar  are: 

1 .  You  can  see  how  the  crop  is  keeping. 

2.  The  conditions  can  be  controlled. 

3.  The  potatoes  can  be  sold  at  any  time. 


STORING  151 

Losses  in  Storage. — Potatoes  suffer  loss  in  weight 
in  keeping  in  addition  to  any  loss  due  to  disease  or 
insect  attacks.  At  Cornell  University,  during  the  past 
winter,  the  variety  Sir  Walter  Raleigh,  stored  in  crates 
in  a  cool  cellar,  lost  12  per  cent,  in  weight  between 
the  date  November  6,  1903,  and  April  27,  1904,  a 
period  of  173  days,  while  the  variety  Carman  No.  3 
lost  nearly  10  per  cent.  Neither  variety  had  sprouted 
at  all.  This  seems  to  show  that  in  this  district  the 
latter  is  better  for  storage,  and  growers  have  noted 
this.  Sir  Walter  Raleigh  seems  better  adapted  for 
selling  from  the  field  than  for  storage.  No  doubt 
other  varieties  vary  in  the  same  way,  and  the  same 
variety  will  vary  under  differing  conditions.  At  the 
Michigan  Experiment  Station  a  barrel  of  potatoes 
stored  September,  1893,  had  lost  5  per  cent,  in  weight 
by  March  28,  and  11.5  per  cent,  by  May  i,  1894.  Re- 
search shows  that  these  losses  are  influenced  by  tem- 
perature and  the  state  of  moisture  of  the  air.  The 
higher  temperature  increases  the  loss,  while  the  higher 
moisture  content  diminishes  it.  I/ight  seems  to  have 
little  influence  upon  the  loss  of  weight,  but  is  injurious 
because  it  diminishes  the  selling  value  of  the  potato. 
The  average  percentage  losses  of  twelve  varieties  of 
potatoes  carefully  stored  in  a  cool  cellar  at  a  tempera- 
ture of  42°  to  51°  F.  during  seven  months,  as  recorded 
by  E.  Wollny,1  are:  October,  2.02  per  cent.;  Novem- 
ber, 1.18;  December,  .50;  January,  .50;  February,  .81; 
March,  .41;  April,  .50;  the  total  loss  aggregated,  on  an 
average,  6.17  per  cent.  In  every  case  the  losses  were 


E.  S.  R.,  III.,  p.  493. 


152  THE  POTATO 

greatest  directly  after  digging,  and  in  February  the 
losses  were  higher  than  the  month  before  or  after. 
The  size  of  the  tuber,  or  whether  the  variety  was  early 
or  late,  had  no  perceptible  influence.  The  three  early 
varieties  lost  from  4.87  to  8.48  per  cent.,  the  five  medi- 
um-early varieties  from  4.55  to  6.78  per  cent.,  and  the 
four  late  varieties  5.71  to  7.28  per  cent.  These  losses 
are  believed  to  be  lower  than  those  usually  assumed 
and  observed.  The  loss  of  weight  of  these  tubers 
from  May  to  October  was  21.57  Per  cent.,  considerably 
more  than  their  loss  from  October  to  May  i .  As  soon 
as  the  sprouts  begin  to  grow  the  loss  is  rapid. 

Nobbe  found  that  about  75  per  cent,  of  the  loss  of 
potatoes  in  storage  is  due  to  loss  of  water  and  25  per 
cent,  to  respiration.  As  the  potato  is  alive  and 
breathes,  its  existence  depends  upon  its  using  some  of 
its  stored-up  energy.  A  ferment  changes  some  of  its 
starch  into  sugar,  and  this  sugar  is  used  to  furnish 
energy.  At  low  temperatures  sugar  formation  contin- 
ues, but  respiration  and  the  use  of  the  sugar  diminishes, 
and  at  30°  F.  to  28°  F.  (2°  to  4°  below  freezing-point) 
respiration  almost  ceases;  hence,  frozen  potatoes  taste 
sweet  because  of  the  accumulation  of  sugar. 

E.  Wollny  believes  that  between  32°  and  50°  F.  is 
the  best  range  of  temperature  for  holding  potatoes. 

The  actual  losses  which  may  occur  in  storage  as  the 
result  of  disease  cannot  be  definitely  stated. 


CHAPTER  XIV 

PRODUCTION,    TRANSPORTATION,    AND 
MARKETS 

IN  the  North  the  potato  is  a  quasi-staple  product. 
It  can  be  kept  a  number  of  months  in  storage.  In  the 
South,  except  in  cold  storage,  it  cannot  be  kept  long 
and  is  purely  a  garden-truck  crop,  but  its  culture  is 
extending. 

2,836,196  farmers  grew  potatoes  in  1899.  The  area 
was  2,938,952  acres,  and  the  yield  273, 328, 207  bushels, 
valued  at  $98,387,614.  The  average  value  of  the 
product  per  acre  was  $33.48,  that  of  all  crops  was 
$10.04,  while  that  of  all  vegetables  was  $42.09  per 
acre.  The  price  per  bushel  varied  between  22  cents 
in  Iowa  and  Nebraska  to  $1.10  in  Arizona,  the 
average  price  being  36  cents.  The  average  yield '  per 
acre  in  the  year  1879  was  96.7  bushels;  in  1889,  83.6 
bushels,  and  in  1899,  93  bushels  per  acre,  although 
yields  of  300  and  400  bushels  are  common,  and  over 
800  bushels  have  been  obtained. 

In  1900  six  States  grew  51  per  cent,  of  the  potatoes 
(Figs.  47,  48) — viz.,  New  York,  Wisconsin,  Michi- 
gan, Pennsylvania,  Iowa,  and  Minnesota — while  Ohio, 
Illinois,  Maine,  Kansas,  Nebraska,  Missouri,  Indiana, 
and  California  grew  25  per  cent.  more.  The  sandy 
pine  belt  region,  skirting  the  lakes,  has  shown  a  phe- 
nomenal increase  in  potato  production.  In  Maine, 


Consult  Twelfth  Census  Report  1902. 

153 


. 


156  THE  POTATO 

Michigan,  Wisconsin,  and  Minnesota  the  potato  acre- 
age has  increased  faster  than  the  population  in  the  past 
ten  years.  New  York  comes  in  the  same  belt.  The 
per  capita  production  of  potatoes  in  the  United  States 
is  given  as  about  3.5  bushels.1  About  one- third  of  the 
total  crop  of  the  Southern  States  is  shipped  North  as 
early  potatoes,  and  some  late  potatoes  are  shipped  back 
from  the  North.  The  consumption  north  of  Mason  and 
Dixon's  line  is  about  4^  bushels  per  head,  exclusive 
of  potatoes  used  for  seed  or  starch-making.  The 
South  consumes  a  relatively  small  amount,  being  less 
than  i  y2  bushels  per  capita. 

Knowing  the  approximate  consumption  and  the 
area  and  condition  of  the  crop  (obtained  from  the 
United  States  Department  of  Agriculture  reports, 
which  are  posted  monthly),  the  farmer  can  form  an 
idea  of  the  outlook  of  the  business.  Thus,  in  1903 
there  were  2,916,855  acres  grown,  and  the  yield  as 
now  known  was  247, 1 27, 880  bushels.  The  table  below 
will  show  the  uses  to  which  this  crop  was  put.  In 
1904  as  large  an  area  would  need  to  be  planted  (a 
larger  one  ought  to  be,  because  the  population  is  in- 
creasing); hence,  10  bushels  of  seed  are  allowed  per 
acre  on: 

Bushels 

2,925  ooo  acres         29,250,000 

Plus  10  per  cent,  loss  in  storage        .     .     .       2,925,000 
Used     for    starch-making,    etc.    (largely 

small  potatoes,  etc.) 5,000,000 

Available  for  human  consumption    .     .     .   209,952,880 


247,127,880 


Consult  Twelfth  Census  Report,  1902. 


PRODUCTION,  TRANSPORTATION,  MARKETS      157 

The  public  can  consume  about  three  bushels  of  pota- 
toes per  head  per  year,  and  as  there  were  79,000,000 
people  to  be  fed,  it  would  require  237,000,000  bushels 
to  furnish  this  quantity.  The  shortage  of  27,000,000 
bushels  insured  a  fair  price,  61.4  cents  per  bushel 
being  the  average  farm  value. 

The  States  having  a  surplus  of  potatoes  are  the 
Southern  and  Eastern  Coast  States  (notably  Maine, 
Rhode  Island,  New  Jersey,  Virginia,  and  Florida), 
their  market  being  the  cities  of  the  East  and  interior. 
The  Trans- Mississippi  and  Nortwestern  States  also 
have  a  surplus. 

The  potato  trade  is  a  home  trade.  The  yield  is  sel- 
dom more  than  is  required  for  home  consumption,  and 
several  times  it  has  been  less — as  in  1902,  when  over 
8,000,000  bushels  were  imported. 

Factors  Influencing  Farm  Prices. — Farm  prices 
are  the  net  value  of  farm  produces  to  the  producer  upon 
delivery  at  the  local  market.  Between  the  grower  and 
the  consumer  profits  must  be  made  by  the  local  buyer, 
the  wholesaler,  the  retailer,  and  perhaps  a  broker  or 
two,  and  the  transportation  companies.  To  yield  a 
profit  to  the  grower  the  price  received  from  the  con- 
sumer must  exceed  (i)  the  expenses  of  distribution, 
including  transportation,  (2)  the  cost  of  production. 
It  may  not.  The  market  price  is  regulated  by  the  law 
of  supply  and  demand. 

In  marketing  live  stock,  cotton,  grain,  tobacco,  and 
wool  the  main  tendency  is  to  eliminate  the  expensive 
middle  man.  This  is  easier  accomplished  with  non- 
perishable  products  than  with  perishable  ones.  There 
are  three  reasons  why  the  expensive  middle  man  has 


158  THE   POTATO 

been  retained  in  the  marketing  of  perishable  prod- 
ucts— 

1.  The  extraordinary  risks  of  depreciation. 

2.  Insufficient  capitalization  of  the  distribution  end. 

3.  Absence  of  large-scale  handling  of  the  products. 
There  is  little  consolidation  in  marketing  potatoes. 

Generally  speaking,  selling  on  commission  is  antiqua- 
ted and  should  be  abandoned,  as  it  is  the  most  demoral- 
izing feature  of  farming.  The  market  is  more  stable 
when  goods  are  bought  and  sold  outright.  An  inter- 
esting feature  is  that  rural  districts  are  doing  more  of 
their  own  banking,  so  far  as  the  financiering  of  the 
grain  and  some  other  crops  is  concerned,  and  the  same 
will  eventually  be  extended  to  potatoes.  Cold  storage 
improves  prices,  preventing  slumps  and  excessively 
high  prices,  both  of  which  are  injurious.  High  prices 
inevitably  lead  to  reduced  consumption.  The  absence 
of  public  markets  where  consumer  and  producer  can 
meet  is  a  noteworthy  feature  of  American  cities  and 
towns.  Such  markets  have  a  salutary  effect  upon  the 
distributor  and  middleman  wherever  they  exist.  The 
useless  retailers  are  eliminated  and  the  service  of  the 
survivor  is  improved,  and  both  producer  and  public 
are  benefited. 

One  important  cause  of  this  lack  of  system  is  the 
poor  roads.  Hauling  is  high.  It  costs,  on  an  average, 
25  cents  to  haul  a  ton  of  produce  a  mile,  and  in  many 
cases  more.  90  per  cent,  of  all  the  freight  handled 
by  the  railroads  is  brought  to  them  on  wagons;  most 
of  it  is  farm  produce.  With  team  and  man  at  $3.50 
per  day,  the  cost  of  hauling  this  freight  aggregates 
about  as  much  as  the  cost  of  running  the  railroads 


PRODUCTION,  TRANSPORTATION,  MARKETS       159 

one  year.  It  is  useless  to  double  the  production  of 
the  farm  unless  we  increase  the  facilities  for  market- 
ing the  produce,  and  to  do  this  it  is  imperative  that  we 
have  good  highways.  In  Belgium  loads  of  farm  prod- 
uce are  hauled  60  to  70  miles  in  competition  with  the 
railroad.  I^et  every  farmer  join  the  good  roads'  move- 
ment; then  he  will  be  able  to  go  to  market  with  prod- 
uce on  days  when  the  land  is  too  wet  to  work  or 
when  the  price  is  high.  How  many  miles  will  $1.25 
haul  a  ton  of  potatoes  or  other  farm  produce  on  a  road, 
a  trolley  road,  a  railroad,  and  on  water  ? 

$1.25  will  haul  a  ton  5  miles  on  a  common  earth 
road  ;  12^  to  15  miles  on  a  well-made  macadam  road; 
25  miles  on  a  trolley  road  ;  250  miles  on  a  steam  rail- 
way; 1,000  miles  on  a  steamship. 

The  value  of  cheap  steamship  transportation  is  seen 
in  the  Eastern  potato  trade.  The  prices  of  potatoes  are 
better  sustained  in  the  Central  States  than  in  the  East- 
ern because,  although  the  tariff  of  25  cents  per  bushel 
is  an  ample  safeguard  for  the  producer,  as  soon  as 
potatoes  are  50  cents  per  bushel,  wholesale  imports  from 
Europe  and  the  West  Indies  are  apt  to  prevent  them 
from  going  much  higher. 

The  South  Atlantic  States,  from  Florida  to  Virginia, 
supply  the  early  potato  trade  of  the  Eastern  cities. 
The  water  transportation  enables  them  to  handle  large 
quantities  at  low  rates,  and  to  compete  with  Northern 
potatoes  (old)  during  at  least  three  months  of  the 
year. 

Modes  of  Selling.— i.  The  Local  Market.— This 
deserves  attention,  as  higher  prices  are  received  in  it 
by  the  producer  than  when  shipped  away. 


160  THE  POTATO 

2.  The  Distant  Market. — Many  growers  must  ship. 
For  such,  combination  is  essential.  The  method 
adopted  by  the  Eastern  Shore  potato  farmers  (Vir- 
ginia) is  noteworthy.  There  are  2,500  shippers  in  the 
Exchange.  They  sell  all  their  produce  through  select- 
ed receivers,  appointed  by  the  directors,  in  New  York, 
Boston,  and  Philadelphia.  The  receivers  charge  8  per 
cent,  commission,  of  which  3  per  cent,  is  given  to  the 
agent  who  solicits  the  business.  This  agent  should 
be  familiar  with  the  market  requirement  and  give  in- 
structions in  regard  to  methods  of  grading,  assorting, 
and  packing,  and  in  this  way  render  the  produce  more 
valuable.  Combinations  such  as  the  following  com- 
mend themselves  :  the  use  of  the  "  registered  label," 
which  is  similar  to  a  "  union  label,"  and  is  placed  on 
all  packages,  or  a  trade-mark  similar  to  that  used  by 
the  Farmers'  Produce  Association,  of  Delaware,  which 
carries  the  number  of  the  shipper,  and  enables  the 
selected  salesman  to  inform  the  grower  at  once  if  any- 
thing is  wrong. 


FARMERS'    PRODUCE    ASSOCIATION 
OF    DELAWARE  (2?) 

The  contents  of  this  package  are 

GUARANTEED 
to  be  as  good  all  through  as  on  top 


Commission  Rates. — In  Cleveland  potatoes  are 
sometimes  sold  on  a  commission  basis  of  4  and  5  cents 
per  bushel,  or  10  per  cent,  of  the  sale  price.  In  St. 


PRODUCTION,  TRANSPORTATION,  MARKETS       l6l 

Louis  the  wholesaler  purchases  and  makes  his  profit 
by  selling  to  large  customers  and  hucksters  at  an  ad- 
vance of  10  cents  per  bushel  over  what  they  cost  him 
in  car  lots. 

In  Cincinnati  the  rate  of  commission  is  3  cents  per 
bushel.  In  Kansas  City  the  brokerage  for  handling  is 
2  to  2^  cents  per  bushel.  In  Richmond,  Virginia,  and 
Atlanta,  Georgia,  if  not  sold  by  the  grower,  10  per 
cent,  is  the  commission.  In  Lincoln,  Nebraska,  when 
potatoes  retail  at  80  cents  per  bushel,  the  money  is 
divided  about  as  follows:  Retailer's  share,  20  cents; 
wholesaler's  share,  10  cents;  railroad  freight,  18  cents; 
seller's  commission,  7  cents;  net  price  to  producer,  25 
cents  ;  69  per  cent,  of  the  cost  to  the  consumer  goes 
to  pay  the  transporters  and  distributors,  and  31  per 
cent,  to  the  grower.  At  Portland,  Oregon,  the  com- 
mission is  5  per  cent. ,  and  the  burlap  sacks  in  which 
the  potatoes  are  handled  cost  about  5  cents  each. 
The  retailers  sell  at  an  advance  of  10  to  30  cents  per 
sack  ( i oo  pounds).  At  New  York  and  Philadelphia 
8  and  10  per  cent,  commission  will  find  good  sales- 
men. The  producer  usually  receives,  net,  between 
25  and  65  per  cent,  of  the  retail  price  of  potatoes. 
Taking  a  number  of  market  returns,  they  show  that 
the  producer's  returns  are  about  63  per  cent,  of  the 
price  paid  in  the  markets,  and  of  this,  in  some  cases, 
about  half  is  paid  to  the  railways  for  transportation  if 
the  goods  are  sent  by  rail,  so  that,  then,  roughly 
speaking,  the  producer,  transporter,  and  distributor 
divide  the  customer's  money  equally.  The  value  of  a 
local  market,  where  the  producer  can  sell  direct  to  the 
consumer,  is  apparent. 


1 62  THE   POTATO 

Grading. — The  proper  grading  of  potatoes  is  essen- 
tial to  success.  Scabby,  second-growth,  ill-shapen, 
diseased,  and  undersized  tubers  must  be  removed 
from  first-class  grade.  The  grading  may  be  done  by 
having  a  sand  screen  on  trestles  set  at  such  an  angle 
that  the  potatoes  roll  down  into  baskets  at  the  bottom, 
while  the  dirt  falls  through,  and  the  seconds  and  refuse 
are  thrown  into  baskets  or  boxes  on  the  side.  Let  two 
men  sort  and  one  shovel,  and  have  one  emptying  and 
bagging  if  they  go  into  bags.  A  sack-holder  is  a  con- 
venience in  filling  the  bag.  The  small  potatoes  and 
dirt  may  be  removed  by  a  potato-sorter  (Fig.  49),  of 
which  there  are  several  types  on  the  market. 

Packages. — Potatoes  are  sold  by  the  pound,  peck, 
bushel,  barrel,  cental,  and  car  lot.  The  early  potatoes 
are  shipped  in  barrels  holding  3  bushels  ( 1 80  pounds) . 
A  canvas  cover  is  nailed  on  the  head.  Such  barrels 
cost  about  20  cents,,  including  the  cover.  The  late 
crop  is  sometimes  shipped  in  bulk  in  car  lots.  In  the 
East  seed  potatoes  are  shipped  in  double-headed  bar- 
rels containing  165  pounds,  net.  Such  barrels  cost, 
new,  about  30  to  33  cents.  Flour-barrels  are  often 
purchased  at  about  1 5  cents  each  instead.  The  high 
price  of  new  barrels  leads  some  to  ship  seed  potatoes 
in  strong  burlap  sacks  which  hold  the  same  amount 
as  a  barrel.  The  sacks  cost  15  to  20  cents  less  than 
the  barrel.  Boxes  are  used  for  shipping  small  quan- 
tities. On  the  Pacific  Coast  burlap  sacks  holding 
a  cental  (100  pounds),  and  costing  5  cents  each,  are 
used. 

Barrels. — Before  filling,  drive  the  hoops  firm  on  the 
bottom  and  nail  with  shingle  nails;  drive  on  the  bulge 


1 64  THE  POTATO 

hoops,  and  secure  with  3  or  4  barrel  nails;  then  pro- 
ceed to  fill.  The  potatoes  should  be  shaken  down  oc- 
casionally while  filling,  and  the  barrels  filled  full,  and, 
if  headed,  the  head  should  be  put  in  where  it  belongs 
with  a  screw  press,  so  that  the  potatoes  cannot  rattle. 
The  head  should  be  nailed  firmly  with  shingle  nails. 
If  in  bags,  sack  them  up  well,  and  tie  tight ;  or  sew 
up,  according  to  requirements. 

Bushel  Boxes. — For  marketing  early  potatoes  in 
the  local  market  bushel  boxes  or  crates  are  often 
used.  T.  B.  Terry  uses  a  bushel  box  13x16  inches 
and  13  inches  deep,  all  inside  measurement.  The 
sides  and  bottoms  are  of  y% -inch,  and  the  ends  are 
^Hj-inch,  white  wood.  Hand-holes  are  cut  in  each 
end,  and  the  upper  corners  are  bound  with  galvanized 
hoop  iron  to  strengthen  them.  They  cost  $25.00  to 
$30.00  per  hundred  at  the  factory,  and  weigh  6  to  7 
pounds  each.  Each  box  has  a  lid,  so  that  in  change- 
able weather  the  potatoes  can  be  picked  up  and  cov- 
ered as  fast  as  dug.  This  box  holds  five  pecks.  The 
legal  bushel  for  grain  is  2,150.4  cubic  inches,  and  in 
measuring  potatoes  the  rule  is  to  heap  the  half-bushel 
measure  sufficiently  to  add  one  level  peck  to  the  two 
level  half-bushels.  Five  level  pecks  are  held  in  2,688 
cubic  inches.  These  boxes  hold  2,700  cubic  inches 
when  level  full ;  hence,  they  may  be  piled  three  or 
four  high  on  a  wagon.  The  recent  introduction  of  a 
crate  in  which  the  sides  fold  onto  the  bottom  when 
not  in  use  reduces  the  amount  of  storage  room  re- 
quired by  about  two-thirds.  These  crates  cost  the 
same  as  others,  and  appear  to  be  equally  strong. 

Advantages  of  a  bushel  box  : 


PRODUCTION,  TRANSPORTATION,   MARKETS      165 

1.  Potatoes  are  put  in  the  boxes  and  covered  as  soon 

as  dug,  thus  preventing  them  from  heating  in 
the  sun. 

2.  They  are  easily    and  quickly  loaded  on  a  wagon, 

saving  time. 

3.  They  are  convenient  packages  in  which  to  carry 

early  potatoes  to  the  home  market. 

4.  The  potatoes  may  be  left  at  the  store  in  the  box  and 

delivered  in  the  box  when  sold,  saving  handling 
and  bruising. 

5.  When  drawing  the  main  crop  to  the  storage-cellar 

they  are  convenient  to  handle. 

6.  They  may  be  used  for  storing  seed  potatoes,  apples, 

etc. ,  and  carrying  seed  potatoes  to  the  field  to 
be  planted. 


CHAPTER   XV 


CHEMICAL   COMPOSITION   AND   FEEDING  VALUE 

Composition. — Early  attempts  were  made  to  deter- 
mine the  food  value  of  the  potato  by  means  of  chemical 
analyses.  In  1795  Pearson  reported  "Experiments 
and  observations  on  the  constituent  parts  of  the  potato 
root."  Einhof  published  analyses  of  the  potato  in 
1805,  as  did  Vanquelin  in  1817.  Rather  more  than 
fifty  years  ago  Emmons  in  this  country  reported  anal- 
yses. Lawes  and  Gilbert  devoted  considerable  time  to 
the  study  of  the  composition  of  potatoes,  and  more  re- 
cently various  agricultural  experiment  stations,  nota- 
bly the  Connecticut  State  and  the  Minnesota  Agricul- 
tural Experiment  Stations,  the  Division  of  Chemistry, 
U.  S.  D.  A.,  and  various  European  institutions  have 
been  investigating  the  problem.  The  approximate 
chemical  composition  of  a  number  of  varieties  is : 
Water,  75  per  cent.;  protein,  2.50  per  cent.;  ether  ex- 
tract, .08  per  cent.;  starch,  19. 87  per  cent.;  fibre,  .33  per 
cent.;  other  non-nitrogenous  materials,  .77  per  cent.; 
ash,  i  per  cent.  A  more  extended  analysis  is  taken 
from  the  Vermont  Experiment  Station,  report  1901: 
TABLE  XII 


v. 

V* 

Ic 

8 

1 

u 

1 

|l 

1 

I'll 

|! 

P 

II 

|l 

!"$ 

11 

Per 

Pei- 

Per 

Per 

Per 

P'r 

Per- 

Per 

Per 

ftr 

cent. 

cent. 

cent. 

cent. 

cent 

ci'nl. 

cent. 

cent. 

cent. 

79-41 

20.59 

14'5' 

1-35 

0.09 

0.36 

2.28 

0.06 

1.26 

0.68 

1 66 


CHEMICAL  COMPOSITION  AND  MARKET  VALUE     167 

The  percentage  of  water  usually  ranges  between  70 
and  80  per  cent.,  the  extremes  being  65  and  85  per 
cent.  Potatoes  contain  more  dry  matter  than  any  root 
crop. 

Per  cent. 

White  turnips        7  to     9 

Rutabagas 9  to  14 

Mangel-wurzels 9  to  16 

Sugar-beets 12  to  24 

Carrots 10  to  17 

Parsnips 10  to  18 

Potatoes 20  to  30 

About  85  per  cent,  of  the  matter  is  present  in  the 
solid  portion,  or  marc,  and  15  per  cent,  in  the  juice. 
It  has  been  believed  by  many  that  the  specific  gravity 
of  the  tubers  varied  with  the  percentage  of  dry  matter, 
and  on  this  basis  tables  for  ascertaining  the  dry  matter 
present  in  the  tubers  from  the  specific  gravity  have 
been  worked  out  and  used  considerably.  From  these 
data  the  starch  content  was  determined.  Woods,1  of 
Maine,  and  Watson,2  of  Virginia,  found  that  the  ratio 
existing  between  the  specific  gravity  and  the  starch 
content  is  not  fixed. 

Starch  is  the  most  important  constituent  of  the  dry 
matter  of  potatoes;  it  generally  constitutes  15  to  20 
per  cent,  of  the  fresh  tubers,  but  may  be  as  low  as  10 
or  as  high  as  25  per  cent.  Maine-grown  potatoes  are 
usually  lower  in  their  starch  content  than  European- 
grown  potatoes.  The  starch  content  varies  with  the 
variety  and  the  locality.  Northern-grown  samples  of 
the  same  variety  usually  contain  more  starch  than 
Southern-grown  samples.3 

»  Me.  Bui.  57,  p.  150.  a  Va.  Bui.  55,  p.  102;  Bui.  56,  p.  144. 

*  Va.  Bui.  56,  p.  144. 


1 68 


THE  POTATO 


TABLE    XIII 
DIGESTIBILITY    OF     POTATOES 


Js 

i 

1 

| 

FOOD 

Animal 

« 

ll 

i 

ll 

b 

'!* 

1 

i 

IT 

•jj 

Potatoes,    with  eggs,    milk, 

cent. 

cent. 

cent. 

and  cream  

Man 

9O.6 

71  .9 

93-o 

.... 

Potatoes,  raw  '  

Pigs 

97-o 

84.5 

82.O 

98.1 

44.6 

Potatoes,  cooked  
Potatoes  dried  a  and  ground. 

Pigs 
Sheep 

82.0 

^ 

80.0 

97.6 
92.0 

40.0 

The  above  data  show  that  potatoes  are  almost 
wholly  digestible. 

Feeding  Value. — When  abundant  and  low  in  price, 
potatoes  may  be  fed  to  all  classes  of  stock.  In  France, 
Girard  fed  55  to  66  pounds  of  cooked  potatoes  per  day 
to  fattening  steers  and  4^  to  6^4  pounds  to  sheep. 
Von  Funke3  found  uncooked  potatoes  were  good  for  all 
stock  except  pigs.  He  fed  60  pounds  of  raw  potatoes, 
6  pounds  of  linseed  meal,  and  9  pounds  of  clover  hay, 
with  salt,  per  1,000  pounds,  live  weight,  per  day  to  fat- 
tening steers.  For  milch  cows,  25  pounds  daily  per 
i  ,000  pounds,  live  weight,  is  the  limit.  For  yearlings, 
ewes,  and  wether  sheep,  25  pounds  per  1,000  pounds, 
live  weight,  per  day  is  advised,  and  fattening  sheep, 
40  pounds.  For  horses,  about  12  pounds  per  1,000 
pounds,  live  weight,  may  be  given  with  other  food. 
Stock  should  not  be  watered  soon  after  feeding  pota- 
toes, but  preferably  about  half  an  hour  before  feeding. 
Potatoes4  are  not  a  valuable  food  for  young  animals, 


1  Snyder,  Minn.  Bui.  42,  pp.  89,  90. 
»  B.  S.  R.,  V.,  p.  812. 


Kellner,  et  a/.   E.  S.  R.,  XIV.,  p.  595. 
Minn.  Bui.  42,  p.  95. 


CHEMICAL   COMPOSITION   AND    FEEDING   VALUE    1 69 

as  they  are  deficient  in  protein  and  ash — hence,  should 
not  be  fed  to  growing  cattle  under  two  years  old, 
lambs,  or  young  pigs,  unless  in  very  small  amounts, 
with  other  food  to  balance  the  ration.  At  Wisconsin 
Experiment  Station,1  hogs  ate  cooked  potatoes  better 
than  uncooked,  and  445  pounds  of  cooked  potatoes  were 
equal  to  100  pounds  of  corn-meal  in  feeding  value. 
One  pound  of  dry  matter  of  corn  is  superior  to  one  pound 
of  dry  matter  of  potatoes  for  making  gains  with  pigs. 
Cooking.  —  In  cooking  potatoes  a  considerable 
portion  of  the  albumen  may  be  lost.  Peeled  potatoes 
started  in  cold  water  lost  80  per  cent,  of  albumen, 
while  those  started  in  hot  water  lost  but  10  per  cent. 
L,ess  is  lost  if  the  potatoes  are  not  peeled.  Salt  should  be 
added  to  potatoes,  because  the  mineral  matter  they  con- 
tain is  deficient  in  sodium  salts,  which  are  requisite  for 
the  human  system,  and  because  salt  increases  the  pala- 
tability.  Varieties  vary  in  the  time  they  require  to 
cook,  and  even  soil  and  climatic  conditions  have  an 
influence.  In  a  floury,  mealy  potato  the  starch  grains 
have  swollen  and  burst,  and  ruptured  the  cell-walls 
surrounding  them,  while  in  a  soggy  potato  this  has 
not  taken  place.  Potatoes  showing  second  growth 
will  not  cook  uniformly;  the  last-grown  portion  will 
cook  first.  When  second  growth  takes  place  the 
starch  passes  from  the  older  portion  to  the  new;  hence, 
when  cooked,  the  older  portion  appears  to  be  hard  and 
dark,  while  the  newer  portion  is  white  and  floury,  the 
difference  being  due  to  the  presence  or  absence  of 
starch. 


i  Wis.   Seventh  Annual  Report,  1890,  and  Henry,  "  Feeds  and  Feeding," 
p.  212. 


170  THE   POTATO 

Uses. — Potatoes  are  used  as  human  food,  stock  food, 
for  the  manufacture  of  starch, 'syrup,  alcohol,  dextrin, 
etc.  Potatoes  may  be  preserved  as  ensilage2  for  stock 
feeding,  while  the  pomace3  resulting  from  starch  manu- 
facture and  potato  feed  4  have  received  attention  for 
the  same  purpose.  Potatoes  may  be  dessicated,  and  in 
this  form  can  be  easily  preserved  in  the  tropics  and 
arclic  regions,  and  thus  furnish  an  excellent  article  of 
diet  in  a  convenient  form  for  transportation.  The  in- 
dustry is  small  at  present,  but  can  be  readily  extended. 


1  U.  S.  D.  A.  Div.  of  Chemistry,  Bui.  58. 

2  U.  S.  D.  A.  Farmers'  Bui.  79,  p.  21. 

a  Me.  Sta  Report,  1896,  p.  28.    Bui.  65,  p.  115. 
*  Vt.  Bui.  82,  p.  72. 


CHAPTER  XVI 

BREEDING  AND  SELECTION— PROPAGATION  AND 
BREEDING 

POTATOES  are  propagated  from  seed,  cuttings,  lay- 
ers of  green  shoots,  sprouts  from  the  eyes  of  tubers, 
or  portions  of  the  tubers  containing  a  bud  or  eye. 
About  the  beginning  of  the  eighteenth  century  Shirreff , 
of  England,  wrote  that  "  the  potato  is  to  be  considered 
a  short-lived  plant,"  and  that  "  the  only  way  to  obtain 
vigorous  plants  and  to  insure  productive  crops  is  to  have 
frequent  recourse  to  new  varieties  raised  from  seed." 
Dr.  Hunter  and  T.  A.  Knight  held  the  same  views. 
T.  A.  Knight  stated  that  late  planting  tended  to  re- 
invigorate  a  degenerating  variety.'  The  value  of  rais- 
ing new  varieties  from  seed  is  recognized  to-day,  and 
for  their  production  some  modern  breeders  sele<5t  as 
parents  two  varieties,  which  in  most  qualities  bear  close 
resemblance  to  each  other,  avoiding  the  use  of  oppo- 
sites,  the  claim  being  that  it  is  easier  to  fix  the  type. 
Others,  including  Burbank  and  Garton,  make  crosses 
between  widely  divergent  types,  although  it  takes 
longer  to  fix  the  ones  they  select  and  there  is  a  lower 
percentage  worth}'  of  a  trial.  There  is,  however,  more 
chance  of  obtaining  something  above  the  average. 
Wide  crosses  act  upon  the  characters  in  the  plant  in  a 
manner  similar  to  a  vigorous  push  on  the  pendulum  of 
a  clock — it  goes  higher  on  each  side:  plants  of  higher 

»  Miller's  "  Gardeners'  Dictionary,"  ed.  :8oy,  "Potatoes,"  and  Don's 
"Gardeners'  Dictionary,"  1831-38,  Vol.  IV.,  pp.  400-406. 

171 


1 72  THE   POTATO 

value  and  plants  of  lower  value  than  either  parent  are 
secured.  A  plant  of  high  value  is  secured  and  grown 
for  a  period  of  years  in  order  to  fix  it.  Those  who 
have  regarded  the  valuable  characters  which  led  tp  the 
selection  of  the  individual  as  fixtures  from  the  beginning 
claim  that  this  period  of  fixing  is  solely  for  the  pur- 
pose of  elimination  of  the  undesirable  characters,  and 
that  it  ought  to  be  termed  ' '  the  elimination  period  ' ' 
rather  than  ' '  the  fixing  period. ' '  The  interrelationship 
of  different  qualities  is  not  well  known,  but  it  has  been 
noted  that  a  variety  having  a  few  thick  stalks  yields 
large  tubers,  but  few  in  number,  while  a  number  of 
weak  stalks  is  often  found  with  a  number  of  small 
tubers.  Early  ripening  and  resistance  to  blight  or  rot 
(Phytophthora  infestans}  are  not  generally  found  to- 
gether. It  is  claimed  that  a  large  production  of  seed- 
balls  goes  hand  in  hand  with  a  small  production  of 
tubers.  T.  A.  Knight  claimed  that  varieties  which  did 
not  bloom  readily  could  be  induced  to  do  so  by  removal 
of  the  soil  from  round  the  tuber-bearing  stems,  the  ex- 
planation offered  being  that  the  plant's  failure  in  tuber 
production  would  stimulate  the  production  of  seed.1 

In  pollenizing  varieties  artificially  the  stamens  should 
be  removed  from  the  female  parent  with  fine  pin- 
cers just  as  the  bloom  opens,  or  before,  and  the  flower 
enclosed  in  a  paper  or  gauze  bag.  The  proper  time  to 
apply  the  pollen  is  known  by  the  moist  appearance  of 
the  stigma.  The  pollen  from  the  desired  variety  should 
be  dusted  on  the  stigma  on  two  or  three  successive 
days.  The  bag  may  be  removed  when  the  stigma  dies 


Philosophical  Transactions,  iSo6. 


BREEDING   AND   SELECTION 


173 


and  the  bloom  \yithers.     The  fruit,  or  seed-ball,  may 

contain  from  100  to  300  seeds.  These  are  washed  from 
the  ripe  seed-balls,  dried,  and  at  the  proper  season 
sown  under  glass,  or  in  a  hot-bed,  or  out-of-doors  in 


KIG.  50 — POTATO  FLOWER,  WITH  CALYX  AND  COROLLA  REMOVED 
On  the  left  are  shown  the  anthers  closed  round  the  pistil.  On  the  right  the 
anthers  are  expanded,  pistil  not  shown  The  inner  surfaces  of  the  anthers 
show  the  line  where  rupture  occurs  when  the  pollen  is  liberated.  Gener- 
ally this  occurs  only  near  the  upper  portion  of  the  anther. 

flats.  The  .seeds  germinate  rapidly.  Later  they  are 
transplanted  to  a  well-prepared  piece  of  land  outside. 
The  distance  apart  varies  with  different  growers — from 
1 2  x  1 2  to  26  x  26  inches,  and  sometimes  more.  The  up- 
right stem  bears  leaves  and  the  axils  of  the  first  leaves 
bear  shoots,  which  turn  downward  into  the  ground 
and  bear  tubers.  The  old  idea  that  the  first  year's 


174 


THE   POTATO 


np-x-t  larger,  and— so 
tuber  weighing  over 


crop  consist  of  small  tubers,  tht 
on,  does  not  always  hold,  as  a 
seven  ounces  has  been 
produced  the  first  year. 
The  Burbank  potato  was 
full  size  the  first  year  it 
was  grown  from  seed, 
and  many  breeders  feel 
that  unless  the  tubers 
are  of  edible  size  the 
first  year  they  are  not 
likely  to  be  worth  fur- 
ther care.  Frequently 
the  tubers_d6~not_ ..reach 
full  size  until  the  second 
year.1  The  tubers  from 
each  plant  must  be  kept 
separate,  the  best  selected 
and  planted  again.  The 
distance  apart  varies  be-  a_stigma,  where  p,,^  is  applied. 

tweeil     26  X  12    and     40  X   .*— Style,  down  which  the  pollen  tube 
i  TTT-J  1  goes  to  the  ovary,  c,  where  it  fertilizes 

40  inches.    Wider  plant-  the  ovllle>  which  become  the  seeds  (see 


FIG.    51  —  1'ISTIL     OF     POTATO 
FLOWER,   SHOWING   THE    PARTS 


Pig-  &•     rf—  Attachment  of  stamens, 
removed  to   prevent  self-fertilization. 

e_  FetalS)  partly  torn  away  to  expose 

ovary.   /—Sectional  view  of  calyx. 


ing  permits   the   Study  of 
*1  ;«^j;    U,     1  TV, 

the     individual.        The 

third,    fourth,     and     fifth 

year  field  culture  is  given, 

and  a  variety  may  be  found  worthy  of  a  name  and 
further  trial  before  distribution.  The  breeder's  aim  is 
to  produce  varieties  which  excel  in  productivity, 
powerjo  resist  diseases,  earliness,  quality,  percentage 


Minn.  Bui.  87,  p. 


BREEDING    AND    SELECTION  175 

of  starch,  and  have  other  desirable  characteristics — as, 
suitable  shape,  color,  depth  of  eyes,  etc. 

Selection. — Hybridizing  is  of  small  value  unless 
attended  by  careful  selection  and  vigorous  elimination 
of  the  poorer  types.  All  potatoes  tend  to  vary  in  cul- 
tivation, either  to  improve  or  degenerate.  This  varia- 
tion is  more  marked  in  some  plants  than  in  others; 
hence,  once  a  variety  is  established,  the  yield  may  be 
materially  increased  and  the  rapid  deterioration  of 
the  variety  prevented  by  selection  of  the  best  plants. 
Selection  must  be  made  in  the  field,  not  from  the  bin. 
The  whole  plant  must  be  considered,  not  a  single 
tuber.  Goff '  showed  that  by  perpetuating  the  most 
productive  and  least  productive  plants  of  Snowflake 
potatoes  the  total  yield  of  the  most  productive  one  for 
two  years  was  322  ounces,  while  that  of  the  least  pro- 
ductive was  but  100  ounces,  and,  summarizing  fourteen 
years'  trials,  the  most  productive  plants  yielded  180 
per  cent,  more  than  the  least  productive.  Bolley,  at 
North  Dakota,  found  that  "equal  weight  pieces  from 
small  or  large  tubers  of  the  same  vine  are  of  equal 
value,  provided  all  are  normally  mature,"*  confir- 
matory evidence  that  the  whole  plant  is  the  unit  of 
selection. 

Growers  may  at  least  maintain  the  productivity  of 
their  stocks  of  potatoes  by  careful  selection  of  the  best 
plants  when  digging,  careful  storage  of  these  tubers, 
and  then  using  all  of  them  for  seed.  These  might  be 
planted  by  themselves  on  a  piece  of  good  land,  and  se- 


1  (N.  Y.)  Geneva  Report,  1887,  p.  85.    Wis.  Report,  1899,  p.  306. 

2  N.  D.  Bui.  30,  p.  243. 


I76  THE  POTATO 

lections  made  from  them  at  the  following  harvest,  the 
best  plants  being  again  retained  for  the  nursery  plat 
and  the  balance  used  as  seed. 

A.  Girard,1  one  of  the  foremost  potato  growers  of 
France,  selects  his  potatoes  every  year  from  those 
hills  whose  foliage  is  especially  luxuriant.  He  uses 
the  variety  Richter's  Imperator,  and  prepares  the  soil 
to  a  depth  of  12  to  1 6  inches,  giving  a  liberal  applica- 
tion of  barn-yard  manure  and  fertilizers,  acid  phos- 
phate, sulphate  of  potash,  and  nitrate  of  soda.  He 
selects,  for  planting,  tubers  weighing  from  3^  to  4 
ounces.  When  he  cannot  get  such,  he  recommends 
that  tubers  of  7  ounces  in  weight  be  cut  in  two,  and 
tubers  of  10^2  ounces  into  three  pieces — always  cutting 
in  the  direction  of  the  greatest  length.  He  insists  on 
the  rejection  of  all  potatoes  weighing  more  than  n 
ounces.  If  the  potatoes  available  for  planting  weigh 
less  than  3^  ounces  he  places  in  each  hill  several 
smaller  tubers,  enough  to  bring  the  total  weight  to 
about  4  ounces.  He  lays  great  stress  on  the  distance 
between  the  plants;  the  rows  are  24  inches  apart  and 
the  tubers  are  planted  19  inches  in  the  rows,  these  dis- 
tances having  been  determined  to  be  best  by  careful 
experiment.  He  advises  early  planting,  as  soon  as 
danger  from  frost  is  past.  The  crop  should  be  well 
worked  and  all  potatoes  kept  covered,  and  the  tops  well 
sprayed  with  Bordeaux  mixture,  and  the  crop  not  dug 
until  all  of  the  tops  have  withered.  Farmers  in  the 
co-operative  experiments  under  his  direction  report 
yields  of  400  to  700  bushels  per  acre  as  common,  and 


1  E.  S.  R.,  V.,  p.  117. 


BREEDING   AND   SELECTION  177 

even  up  to  1,353  bushels  per  acre  with  a  starch  content 
of  20  to  25  per  cent.  One  farmer  secured  almost 
10,000  pounds  of  starch  per  acie,  probably  one  of  the 
largest  yields  of  carbohydrates  ever  obtained  from  an 
acre  of  land. 


APPENDIX 

Spray  Calendar 


Disease 
or 
Insect 

Spray 
Mixture 

First 
Spraying: 

Second 
Spraying 

Third 
Spraying 

Fourth 
Spraying 

REMARKS 

Early 
Blight 

Bor- 
deaux 
mixture 

When 
plants 
are  4  to 

7  to  14 
days 
later 

7  to  14 
days 
later 

7  to  14 
days 
later 

6  in.  tall 

l^ate 
Blight 

Bor- 
deaux 
mixture 

As  for 
blight 

do.. 

do. 

do. 

Up  to  7  spray- 
ings are  some- 
times given 

Rosette 

Treat  the 
seed 

Flea- 

Bor- 

When 

Repeat 

As  for 

A  deterrent 

beetle 

deaux 

beetles 

if  neces- 

i and  2 

only 

mixture 

appear 

sary 

Colorado 
Potato- 
beetle 
or 

Paris 
green  or 
other 
arsenites 

When 
beetles 
appear 

Repeat 
if  neces- 
sary 

As  for 
i  and  2 

i  pound  Paris 
green  per  acre 
in  100  gallons 
or  more  of  Bor- 

" Bugs" 

iu   Bor- 

deaux mixture. 

and 

deaux 

Ar  sen  ate  of 

Blister- 

mixture 

lead,  3  pounds 

beetles 
or  old- 

to   50   gallons. 
Arseni  t  e   of 

fashion- 
ed Potato 
bug 

lead,  3  pounds 
to   50   gallons. 
Green  arsen- 

oid    i    pound 

per  loo  gallons. 

Grass- 

Paris 

When 

Repeat 

As    for   Colo- 

hopper 

green  or 

they 

if  neces- 

rado beetle 

other 

appear 

sary 

arsenites 

in  Bor- 

deaux 

mixture 

179 


i8o 


THE  POTATO 


Seed   Treatment 

Disease  Treatment 

Scab      .......     Soak  uncut    seed    in     formalin,    i 

pound  to  30  gallons  of  water,  for 
two  hours;  then  dry  and  plant  on 
scab-free  soil. 

Rosette  (fikizoctonia)        .     As  for  scab. 

Dry  Rot    ......     Diseased  tubers   to   be   destroyed; 

those  in  contact  with  them  to  be 
treated  as  for  scab  and  sprayed 
as  for  blight. 

Wet    Rot  (due  to   Blight 

or  Bacteria)  ....  Have  seed  potatoes  in  such  storage 
that  they  can  be  examined,  and 
these  tubers  sorted  out  and  de- 
stroyed. Do  not  plant  affected 
tubers.  Soaking  them  in  forma- 
lin, as  for  scab,  is  advisable  in 
some  cases,  depending  on  the 
cause. 

Stem    Rot    or   Dry    End 
Rot  (Fusarium  oxyspo- 
rum)  .......     It  attacks  the  stem-end  first;  hence, 

cutting  off  this  end  of  suspected 
tubers  will  reveal  the  disease. 
Discard  diseased  tubers. 


INDEX 


PAGE 

Acid  Phosphate  .....  43,47,119 

Acme  Harrow    .........     23 

Ammonium  Salts  as  Fertilizers    31 
82,  42,  47,  119 

Area  in  Potatoes  in  1899    .   .  153,  150 
in  1903  ............    156 

Arizona  Potato  ......... 

Arsenate  of  Lead  .....   135,  137 

Arsenical  Poisoning  ....  133,  127 

Arsenious  Oxide  ........    188 

Arsenite  of  Lead  ....  135,  137,  138 

Lime  ...........  135,  138 

Soda  .............    135 

Available  Phosphoric  Acid    .   .     43 


40,41 


.  161, 


Bacteria,  Useful  . 
Bacterial  Diseases 

Bags 

Barium  Arseuite 138 

Barn  Manure  .   .   .  36,37,44,46,119 

Amounts  used 36,  37 

Barrels 162,  164 

Filling 162 

Size  of 162 

Bermuda  Potato 4,  5 

Black  Death 185 

Blight,  Early,  or  Leaf  Spot  Dis- 
ease   118,  178 

112,113-117,121,178 
,  .  .  127,178 

4.  5 

172 

16, 172 

Bordeaux    Dust,    or    Dry    Bor- 
deaux   130 

Bordeaux  Mixture  .  115,  113, 118,  123 
124,  128, 131 

Benefits  from  Use  of  .  115, 118, 124 
131, 132 

for  Flea-beetles 123, 124 

Mixing 129 

Strength  of  Solution 130 

Testing 130 

Botany 1-7 

Boxes 162 

Bushel       164, 165 

Hiv.-.ling 171 

Buckwheat 29 

as  a  Cover  Crop 29 

in  a  Rotation 29 

Bug  Death 135 


Late,  or  Rot 
Blister  Beetles 
Blooms 

Encouraging 
Blossoming 


PAGE 

Bugs,  or  Potato  Beetle  .  .  .  124, 125 
Bundle  Blackening,  or  Dry  End 

Rot 122,179 

Bushel,  Weight  of  a 162 


Calcium,  Influence  of  ...    .  35,  36 

Calco  Green 138 

Carbon  Bisulphide 126 

Castor  Pomace 32 

Cellars,  Construction  of  ....    149 

for  Storing 149,150 

Temperature  of 150, 152 

Ventilation  of 150 

Chloride,  Calcium,  injurious  .  .     34 
Chlorides,  Injurious  to  Growth, 

34,  43 
Varieties  with  Heavy  Foliage 

Readily  Injured  by 34 

Climate,   Influence  of  .   .  8,  66,  111 
Clover,  Value  for  Plowing  Un- 
der    27,  28 

Red 27 

Crimson 27,  28 

Sweet 28 

Clover,  Influence  on  Yield  ...     27 

Cold  Storage 153,  158 

Color  of  Skin 76 

Colorado  Beetle 124,  125 

Commission  Rates 160,  161 

Composition,  Chemical  132, 166, 167 

Influenced  by  Spraying.  .  .   .    132 

Consumption  of  Potatoes  .  156,  157 

Cooking 169,  170 

Quality 70,  72-74 

Co-operative  Methods  of   Mar- 
keting     160 

Copper  Arsenite 138 

Sulphate 128,  129 

Cottonseed- meal 32,  48 

Cost  of  Selling 161 

Cover  Crops 28,  29 

Cow-ness,  Value   for    Plowing 

Under 27,  28 

Crepidodera  cucumeris,  or  Flea- 
beetle  123 

Crop  Producing  Power  of  Soil 

Reduced 18 

Cultivation 105-109 

Method  of 107 

Tools  Used  In 107 

Cultivations,  Number  of  .  .  105,  106 


I  82 


PAGE 

Culture,  Levei 107 

Systems  of «J 

Cutworms 


127 


Darwin's  Potato 1 

Date  of  Planting 96 

Depth  of  Planting 93-96 

Influence  on  Quality 96 

Influence   on   Tuber    Forma- 
tion       94,  95 

Dessicated  Potatoes 170 

Digestibility  of  Potatoes  ....  168 
Diggers,  Mechanical ....  144-146 
Digging  the  Crop 117,  143 

Methods   .   .   . 143,  144 

Disease  Resistance  Required  in 
a  Variety 71 

Relation  of  Temperature  to  . 
Disease-resisting  Varieties  .  75,  116 

Disk  Harrow 23,24 

Disparene 135,  137 

Distance  Apart 91-93 

Doryphora  decemlineata,  or  Po- 
tato Beetle 124,   125 

juncta,  or  Southern   Potato 

Beetle 124 

Drainage 17,  116 

Dried  Blood 31 

Drills 106 

Dry  End  Rot 122 

Dry  Rot 122 


Early  Blight 118,  179 

Planting 97 

Ensilage,  Potato 170 

Epicauta  vitatta 127 

Epitrix    subcrinata,    or    Flea- 

beetle 124 

Eyes 6 

Depth  and  Frequency  of  .  .  71,  79 
Relation  of  Number  of  Stalks 
Producedto 62,  63 


Farm  Prices 157,  161 

Feed,  Potato 170 

Feeding  Potatoes  to  Stock  .  168,  169 

Value 168,  169 

Fertilizers 30,  31,  37-40 

Amounts  Used 30,  37,  38 

Applying 48 

Compounding  ........     46 

Cost  of 45 

For  Early  Potatoes    ....  35,  39 

Function  of 39-41 

Important  Ingredients  in     .  42,  43 
Influence  of  Period  of  Growth 
Upon  the  Necessary  ....     31 

Mixing 46,  47 

Poor  Mixtures  of 47,  48 

Profit  from  Use  of 37,  38 


PAGE 

Fertilizers,  Purchasing  .  42, 43,  44,45 
Value  of  Home  Mixing  of  .  .  46 
Valuable  ....  87,  38,  40, 176, 177 

Valuing 39,40,43-46 

Fixing  New  Varieties 172 

Flavor 60,  74 

Flea-beetle 82, 114, 118, 123 

Punctures  Injurious  .   .  82, 114, 118 

Flowers 3,  5 

Formalin 69,  118, 119, 122 

Too  Strong  a  Solution  Injuri- 
ous   .     69 

Fungicides 128 

Fufiurium  oxysporum    .   .   .122,  179 


Gelechia  Operculella  Zell.,  Po- 
tato Worm 1 25,   12C 

Good  Roads,  Value  of  ...  158,   159 

Grading  Potatoes 162 

Grasshoppers 126 

Green  Arsenite 135 

Green  Arsenoid 135,  138 

Growth,     Conditions   Influenc- 
ing .  8, 16,  30 

Effect  of  Chlorides  on  ....     84 
Influence  of  Dry  Weather  on  .       9 

Manuring 80 

Influence  of  Respiration  on  .       9 
Influence  of  Time  of,  on  Fer- 
tilizing       31 

Obstructions  to Ill,  127 

Period  of 14,  31 


Habitat  of  Potato 1 

Hammond's  Slug  Shot 135 

Harrow,  Acme 23 

Disk 24 

Spike-tooth 107 

Spring-tooth 23,  24 

Harrows,  Action  of,  on  the  Soil    24 

Harvesting 143 

Methods  of 143 

Hauling  Farm  Produce  .  .    158, 159 

Cost  of 158,159 

Haulm      34,71,80,81 

Hellebore 135 

Hilling 14,16 

Time  of 16 

Hills 106 

Humus,  A  Food  for  Bacteria  .  .     41 
Effects  on   Physical   Proper- 
ties of  the  Soil 23 

In  Soils 21,41,42 

Influence  of  Tillage  on  ....    105 

Influence  on  Depth  of  Plowing    21 

Influence  on  Soil  Moisture  .  .     23 

Hybridizing 171-173 


Imports  of  Potatoes 157 


INDEX 


183 


PAGE 

Insecticides 135,136 

Insuluble  Phosphate  of  Lime   .     43 
Introduction  into  Virginia  ...       2 

into  Europe 3,  7 

Irrigation,    Amount   of    Water 

Used  in 48,  49 

Dangers  of 49 

Value  of    ..........  48,  49 


June  Bug  . 


Kainit 43,48,119 

Kno-bug 135 


Lachnosterna 126 

Late  Planting 97 

Laurel  Green 135, 138 

Leaf 71,81,8-2, 114, 131,  132 

of  Rust-resistant  Varieties  of 
Wheat 82 

Spot  Disease,  or  Early  Blight 

118,  178 

Value  of  a  Tough,  Hard  .   .   81,82 
Level  Culture 106,107 

Objections  to 106 

Light,  Influence  on  Yield    ...       8 
Lime &5,  36,  41, 119, 128 

Uses 41, 128 

Liming     31,32 

London  Purple 135 

Loss  of  Potatoes  in  Storage  151,152 


Macrosporium  solani,  or  Early 

Blight 118,  178 

Manure 30,36,37,44 

Amounts  Applied 36,  37 

Influence  of 30 

Value     44-46 

Manuring,  Reasons  for 80 

Marketing,  Cost  of 160, 161 

Markets 157, 158 

Distant 157,160 

Local 159, 161 

Maturity,  Time  of 71,79,80 

Melanoplus  sp 126 

Mexican  Potato 1 

Moisture,  Conservation  of  Soil,  22, 23 

Influence  of 8,  9 

Mulch,  Soil 106, 109 

Mulching 110 


Nitrate  of  Soda  .  .  .  31,  82, 42,  47,  48 

Effect  on  Buds 69 

Nitrates 42 

Nitrogen 80,31,42 

Effect  of  Excess 81 

Influence  of 81 

Occurrence  in  Fertilizers  .  .     42 


PAGE 

Nitrogen  of  Barn  Manure  ...  36 
Requirement  while  Young  .  .  81 
Sources  of 81,42 

Nozzles 141,142 


Organic  Nitrogen  of  Fertilizers    42 
Oospora  scabies  (Thax.;,  Scab, 

119,  121 

Packages 161 

Paragrene 1&5, 138 

Paris  Green  .  .  124, 125,  127, 135,  336 

Amount  to  use 125, 127 

for  Flea-beetles 124 

for  Potato  Beetles 125 

Peas  in  Rotation a7 

Phosphatic  Fertilizers  .  35,  42,  43,  47 

Effect  on  Maturity 35 

Phosphoric  Acid,  Influence  of  .     35 
Phytophthora  infestans.  Blight 

or  Rot 112-117,121 

Pits 147-149 

Pimply  Potatoes 124 

Pink  Arsenoid 135,  137 

Planters 100-104 

Hand 100, 101 

Horse 101-104 

Planting,  Date  of 96,97 

Depth  of 14,93-96 

Distance  Apart 91-93 

Early  and  Late 97 

Hand 59.  97-100 

Influence  of  Depth  on  Depth 

at  which  Tubers  Form  .  .    94-% 
Influence   of    Depth   of,   on 

Quality 96 

Methods  of 59,  97-100 

Plow,  Potato  or  Shovel 144 

Plowing 21-28 

Conditions  Governing  .  .  .  21,22 

Deep 21,42 

Depth  of 21,22 

Fall 21 

Plowing,  Spring 22 

Pollen 3,  172 

Pollenizing 172 

Pomace,  Potato   .  . 170 

Potash,  Amounts  Applied  .   .  35,  38 

Influence  of 31,  as 

on  Leaves 82 

on  Quality 33,  34 

on  Roots 32,  33 

on  Starch  Formation    .  .  33,  84 

on  Tubers 32,  33 

Muriate  of.   .   .   .33,84,38,43,119 

Amounts  Used 88 

Sources  of 38 

Sulphate  of    ....  S3,  34, 43, 119 

Potassic  Fertilizers 43 

Potassium  Ferro-Cyanide   ...   130 

Potato  Beetle 12*    125 

Bug,  Old  Fashioned  .  .  .  ]<•?,  {78 


I»4 


INDEX 


Potato,  seed 5'6'1S 

Stalk  Weevil 126 

Worm 125,  126 

Preparation  of  Land 21-23 

Pressure  Required  for  Spraying.  140 

Prices,  Average 153 

Farm 157 

in  Eastern  and  Central  States .  159 

Production 153-157 

Propagation 171 

Pumps 140 

Quality,  Cooking 70 

Influence  of  Depth  of  Tubers 

on 96 

Quick  Death 135 

Rainfall,  Amount  Sufficient  .  48,  49 

Rape  as  a  Cover  Crop 29 

Respiration 9, 10, 152 

Influence     of     Temperatore 

on 9,  10 

Rhizoctoniasolani 118,  179 

Roads 158 

Roots 6, 10,  55 

Character  of 11,14,15 

Depth  of 11,14,  15 

Effects  of  Tillage  on 14 

Rosette  Disease 118,  179 

Rot,  or  Late  Blight  .  112, 113-117, 121 
Rotation  .  26-29, 116, 118, 119, 121, 127 

Factors  in 26,  27,  50 

Five-course 26 

Four-course 26 

Leguminous  Crops  in  a    .   .  27,  28 

Maine 26 

Ohio 27 

Three-course 26 

Rust-resistant      Varieties       of 

Wheat 82 

Rye 27-29, 120 

Sack-holder 162 

Sacks,  Cost  of 161,162 

Scab 119,121 

Scheeles  Green 135 

Season,  Influence  of 66,  111 

Second  Growth 12,85 

Seed 5,6,173 

Amount  per  Acre 63,  64 

Bud,  Stem  Ends,  and  Middles.    66 

Cost  of 64 

Cutting 60 

Effect  of  Insufficient  Amount.  104 
Importance  of  a  Good  Strain 

of 51,53 

Proper  Storage  of  ....    52,  63 

Selection 52,  74, 175 

Influence  of  Altitude    .'.  .  .     52 
Management      Previous      to 
Planting 53 


PAGE 

Seed,  Methods  of  Storing    .  .    53,  54 
Northern  and  Southern    ...     51 
Relation  of  Number  of  Stalks 
to  the  Eyes  on  ......    62,  63 

Relation  of  Weight  to  Viabil- 
ity of  ...........     67 


Single  Eyes 

Size  of 

Source  of 

Sprouting 

Time  to  Cut 

Treatment  for  Diseases 

Uses  of  Second  Crop  for 

Viability  of 

Whole  and  Cut 
Seed-balls 
Selection 


62,64 

61-65,67,175 
51 

53-60 
61 

.    179 
52,  53 
66,69 
60-63,65 
1,5,173 
,175 


Shape  of  Tuber  .......  5,71,78 

Shovel,  Potato  .........    147 

Size  of  Tubers,  Variation  in    .   .      75 
Skin  ..........  5,  71,  78,  120 

Colorof  ............   76 

Cracked  ............   84 

Desirable    .........  '  .  .   78 

Soil  Moisture,  Conservation  of 

22,23 
Soils  ...........    17-25,  153 

Changes  in  ..........      41 

Chemical     Composition    and 


Crop  Producing  Power  of 
Composition  of  New  York     .      39 
Diminished   Crop    Producing 

Power  of  ..........      18 

Ingredients  Removed  by  Pota- 

toes from    ........    39,40 

Preparation  of  .......    21-23 

Relationship  of  Varieties  to  19,  87 


Sandy  Loam 
Solanum  commersoni 


17 
1 
1 
1 

1,8 
1 

.  .      48 
162 

.  .    167 
178 

140,  141 
139 

132,  134 
141 


Solanum  jamesii 
maglia 
tuberosum 
var.  Boreale 

Sol  uble  Phosphate  of  Lime 

Sorters,  Mechanical 

Specific  Gravity  of  Tubers 

Spray  Calendar 

Spraying  Attachments    .   . 
Cost  of 

Effect  on  Yield    .   .       .   . 
Hose 

Spraying,  Machines  ......    140 

No/zles  ..........  141,  142 

Pressure  Required  for  ....    140 

Profits  from  .........    139 

Pump  .............    140 

Tanks  .............    141 

Time  of  ............    134 

Sprayings,  Number  of  ...  134,  135 

Sprays  and  Spraying  .   .   .    128-142 

Spring-tooth  Harrow     ....  23,  24 

Starch  .31.  72,  73,  78,  132,  167,  170,  177 
Content  and  Specific  Gravity  .  167 


INDEX 


PAGE 

Starch,  Distribution  in  the  Tuber 

72,73,78 

Production 31,  132,  177 

Stem  Rot 122,  179 

Storage 52,  143-152 

in  Cellars 149,  150 

in  Pits 147-149 

Losses  in 143,  151,  152 

Temperature  for    .   .  53,  151,  152 

Striped  Blister  Beetle 127 

Subsoiling 20,  21 

Sulphur 120 

Hun  Scald Ill 

Sweet  Clover  as  a  Green  Manure,    28 


Tanks  ..............    141 

Tile  Drainage   .........     17 

Tillage  ......  14,  42,  105,  106,  109 

Deep  .............     14 

Objects  of  ..........    106 

Shallow  ........    14,  195,  109 

Value  of   ...........     42 

Tip  Burn  ..........  Ill,  112 

Tobacco  Leaf  Miner  ....  125,  126 

Tools  f  or  Ctilti  va  tion  .   .   .   .    107-109 

Surface  fitting  ........     23 

Tomato  Worm  .........    127 

Transportation,  Cost  of  ....    159 

by  Bail  ............    159 

by  Road  .........  158,  159 

by  Water   ..........    159 

Trays  .............  54,  60 

Trifhulxiriti   trinotata  .....    126 

Tuber  Formation    .    6,  16,  54,  55,  94 

95,  172 

Depth  of  .......  54,  55,  94,  95 

Retarding  of  .........    172 

54,  55 


Stimulation  of 


Tubers,  Hollo 
Number  Formed  by  a  Plant  .     74 
Rate  of  Growth  of  ......     16 

Size  of  Seedling  .....  173,  174 

Type,  Varieties  Not  True  to  .  72,  85 


Unit  Value  of  Fertilizers  ....     44 
Uses  of  Potatoes 170 


Value  per  Acre 153 

Varieties  .   .  19,  51,  72,  75,  76,  a3-90 
171-174 

Breeding  New 171-174 

Disease-resisting 76 


Varieties,  Duplication  and  Re- 
naming of 85, 86 

Fixing  New 172 

Importance  of  New 171 

Improvement  in 84 

Influence  of  Soil  and  Condi- 
tions on 19,  87 

Influence  of,  on  Yield    ....     75 

Life  of  Modern 83 

Life  of  Older 83,84 

List  of 88-90 

Most  Popular 87-90 

Staying  Power  of 83 

Testing 86 

True  to  Name 85 

True  to  Type 72 

Variety,  Selecting  a 70-90 

Variation  in  the 52-54 

Viability  of  Tubers 66-69 

Vigor  of  the  Plant  .   .    71,  82-85,  118 
Indications  of  Deficiency  in  .  84,85 


Washing  Soda  and  Copper  Sul- 
phate Mixture  131 

Water,  Available 48 

Requirement &3,  48-50 

Effect  of  Fertilizers  on  ...     33 
Per  Pound  of  Dry  Matter    .     50 

Weeder 108 

Weeds,  Injurious 105 

Wet  Rot 121, 122 

Whale  Oil  Soap 136 

Wheat,  Depth  at  which  Roots 

Form 15 

Varieties  Resistant  to  Rust  .     82 

White  Arsenoid 138 

Wild  Potato 1 

Wireworms 127 

Wood  Ashes 43, 119 


Yield  .   .  7, 14,  26-28,  70,  74,  75,  84,  87 
132,  134,  153 

Average 74, 153 

Effects  of  Sprouting  Upon  .  .  58 
Influence  of  a  Crop  of  Clover 

on 27,28 

Influence  of  Light  Upon  ...  8 
Influence  of  Soil  on  ...  19,  20,  87 
Influence  of  Spraying  on  .132,  134 
Influence  of  the  Variety 

Upon 19,20,75,87 

Maximum 74 


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little  book  on  Alfalfa  a  few  years  ago  has  been  a  profit  revela- 
tion to  thousands  of  farmers  throughout  the  country,  and  the 
increasing  demand  for  still  more  information  on  the  subject 
has  induced  the  author  to  prepare  the  present  volume,  which 
is  by  far  the  most  authoritative,  complete  and  valuable  work 
on  this  forage  crop  published  anywhere.  It  is  printed  on  fine 
paper  and  illustrated  with  many  full-page  photographs  that 
were  taken  with  the  especial  view  of  their  relation  to  the  text. 
336  pages.  &/2  x  9  inches.  Bound  in  cloth,  with  goid  stamp- 
ing. It  is  unquestionably  the  handsomest  agricultural  reference 
book  that  has  ever  been  issued.  Price,  postpaid  .  .  .  $2.00 

Clean  Milk 

By  S  D.  BELCHER.  M.D.  In  this  book  the  author  sets  forth 
practical  methods  for  the  exclusion  of  bacteria  from  milk, 
and  how  to  prevent  contamination  of  milk  from  the  stable  to 
the  consumer.  Illustrated.  5  x  7  inches.  r46  races. 
Uoth •  -  •  --...  $i.rx> 


Bean  Culture 

By  GLENN  C.  SEVEY,  B.S.  A  practical  treatise  on  the  pro- 
duction and  marketing  of  beans.  It  includes  the  manner  of 
growth,  soils  and  fertilizers  adapted,  best  varieties,  seed  selec- 
tion and  breeding,  planting,  harvesting,  insects  and  fungous 
pests,  composition  and  feeding  value :  with  a  special  chapter 
on  markets  by  Albert  W.  Fulton.  A  practical  book  for  the 
grower  and  student  alike.  Illustrated.  144  pages.  5x7 
inches.  Cloth $0.50 

Celery  Culture 

By  W.  R.  BEATTIE.  A  practical  guide  for  beginners  and  a 
standard  reference  of  great  interest  to  persons  already  engaged 
in  celery  growing.  It  contains  many  illustrations  giving  a  clear 
conception  of  the  practical  side  of  celery  culture.  The  work 
is  complete  in  every  detail,  from  sowing  a  few  seeds  in  a 
window-box  in  the  house  for  early  plants,  to  the  handling 
and  marketing  of  celery  in  carload  lots.  Fully  illustrated. 
150  pages.  5x7  inches.  Cloth $0.50 

Tomato  Culture 

By  WILL  W.  TRACY.  The  author  has  rounded  up  in  this 
book  the  most  complete  account  of  tomato  culture  in  all  its 
phases  that  has  ever  been  gotten  together.  It  is  no  second- 
hand work  of  reference,  but  a  complete  story  of  the  practical 
experiences  of  the  best  posted  expert  on  tomatoes  in  the  world. 
No  gardener  or  farmer  can  afford  to  be  without  the  book. 
Whether  grown  for  home  use  or  commercial  purposes,  the 
reader  has  here  suggestions  and  information  nowhere  else 
available.  Illustrated.  150  pages.  5x7  inches.  Cloth.  $0.50 

The  Potato 

By  SAMUEL  FRASER.  This  book  is  destined  to  rank  as  a 
standard  work  upon  Potato  Culture.  While  the  practical  side 
has  been  emphasized,  the  scientific  part  has  not  been  neglected, 
and  the  information  given  is  of  value,  both  to  the  grower  and 
the  student.  Taken  all  in  all,  it  is  the  most  complete,  reliable 
and  authoritative  book  on  the  potato  ever  published  in  America. 
Illustrated.  200  pages.  5x7  inches.  Cloth $0.75 

Dwarf  Fruit  Trees 

By  F.  A.  WAUGH.  This  interesting  book  describes  in  detail 
the  several  varieties  of  dwarf  fruit  trees,  their  propagation, 
planting,  pruning,  care  and  general  management.  Where  there 
is  a  limited  amount  of  ground  to  be  devoted  to  orchard  pur- 
poses, and  where  quick  results  are  desired,  this  book  will  meet 
with  a  warm  welcome.  Illustrated.  112  pages.  5x7  inches. 
Cloth $0.50 


Cabbage,  Cauliflower  and  Allied  Vegetables 

By  C.  L.  ALLEN.  A  practical  treatise  on  the  various 
types  and  varieties  of  cabbage,  cauliflower,  broccoli,  Brussels 
sprouts,  kale,  collards  and  kohl-rabi.  An  explanation  is  given 
of  the  requirements,  conditions,  cultivation  and  general 
management  pertaining  to  the  entire  cabbage  group.  After  this 
each  class  is  treated  separately  and  in  detail.  The  chapter 
on  seed  raising  is  probably  the  most  authoritative  treatise  on 
this  subject  ever  published.  Insects  and  fungi  attacking  this 
class  of  vegetables  are  given  due  attention.  Illustrated.  126 
pages.  5x7  inches.  Cloth $0.50 

Asparagus 

By  F.  M.  HEXAMER.  This  is  the  first  book  published  in 
America  which  is  exclusively  devoted  to  the  raising  of  aspara- 
gus for  home  use  as  well  as  for  market.  It  is  a  practical 
and  reliable  treatise  on  the  saving  of  the  seed,  raising  of  the 
plants,  selection  and  preparation  of  the  soil,  planting,  cultiva- 
tion, manuring,  cutting,  bunching,  packing,  marketing,  canning 
and  drying,  insect  enemies,  fungous  diseases  and  every  require- 
ment to  successful  asparagus  culture,  special  emphasis  being 
given  to  the  importance  of  asparagus  as  a  farm  and  money 
crop.  Illustrated.  174  pages.  5x7  inches.  Cloth.  .  $0.50 

The  New  Onion  Culture 

By  T.  GREINER.  Rewritten,  greatly  enlarged  and  brought 
up  to  date.  A  new  method  of  growing  onions  of  largest  size 
and  yield,  on  less  land,  than  can  be  raised  by  the  old  plan. 
Thousands  of  farmers  and  gardeners  and  many  experiment 
stations  have  given  it  practical  trials  which  have  proved  a 
success.  A  complete  guide  in  growing  onions  with  the  great- 
est profit,  explaining  the  whys  and  wherefores.  Illustrated. 
5x7  inches.  140  pages.  Cloth $0.50 

The  New  Rhubarb  Culture 

A  complete  guide  to  dark  forcing  and  field  culture.  Part 
I — By  J.  E.  MORSE,  the  well-known  Michigan  trucker  and 
originator  of  the  now  famous  and  extremely  profitable  new 
methods  of  dark  forcing  and  field  culture.  Part  II — Compiled 
by  G.  B.  FISKE.  Other  methods  practiced  by  the  most  experi- 
enced market  gardeners,  greenhouse  men  and  experimenters  in 
all  parts  of  America.  Illustrated.  130  pages.  5x7  inches. 
Cloth $0.50 


Alfalfa 

By  F.  D.  COBURN.  Its  growth,  uses,  and  feeding  value. 
The  fact  that  alfalfa  thrives  in  almost  any  soil;  that  without 
reseeding,  it  goes  on  yielding  two,  three,  four,  and  sometimes 
five  cuttings  annually  for  five,  ten,  or  perhaps  100  years;  and 
that  either  green  or  cured  it  is  one  of  the  most  nutritious 
forage  plants  known,  makes  reliable  information  upon  its  pro- 
duction and  uses  of  unusual  interest.  Such  information  is 
given  in  this  volume  for  every  part  of  America,  by  the  highest 
authority.  Illustrated.  164  pages.  5x7  inches.  Cloth.  $0.50 

Ginseng,  Its  Cultivation,  Harvesting,  Market- 
ing and  Market  Value 

By  MAURICE  G.  KAINS,  with  a  short  account  of  its  history 
and  botany.  It  discusses  in  a  practical  way  how  to  begin  with 
either  seed  or  roots,  soil,  climate  and  location,  preparation, 
planting  and  maintenance  of  the  beds,  artificial  propagation, 
manures,  enemies,  selection  for  market  and  for  improvement, 
preparation  for  sale,  and  the  profits  that  may  be  expected. 
This  booklet  is  concisely  written,  well  and  profusely  illus- 
trated, and  should  be  in  the  hands  of  all  who  expect  to  grow 
this  drug  to  supply  the  export  trade,  and  to  add  a  new  and 
profitable  industry  to  their  farms  and  gardens,  without  inter- 
fering with  the  regular  wo' ....  New  edition.  Revised  and  en- 
larged. Illustrated.  5x7  inches.  Cloth.  ,  ,  .  $0.50 

Landscape  Gardening 

By  F.  A.  WAUGH,  professor  of  horticulture,  university  of 
Vermont.  A  treatise  on  the  general  principles  governing 
outdoor  art;  with  sundry  suggestions  for  their  application 
in  the  commoner  problems  of  gadening.  Every  paragraph  is 
short,  terse  and  to  the  point,  giving  perfect  clearness  to  the 
discussions  at  all  points.  In  spite  of  the  natural  difficulty 
of  presenting  abstract  principles  the  whole  matter  is  made 
entirely  plain  even  to  the  inexperienced  reader.  Illustrated. 
152  pages.  5x7  inches.  Cloth $0.50 

Hedges,  Windbreaks,  Shelters  and  Live  Fences 

By  E.  P.  POWELL.  A  treatise  on  the  planting,  growth 
and  management  of  hedge  plants  for  country  and  suburban 
homes.  It  gives  accurate  directions  concerning  hedges;  how 
to  plant  and  how  to  treat  them;  and  especially  concerning 
windbreaks  and  shelters.  It  includes  the  whole  art  of  making 
a  delightful  home,  giving  directions  for  nooks  and  balconies, 
for  bird  culture  and  for  human  comfort  Illustrated.  140 
pages.  5x7  inches.  Cloth $0.53 


Farmer's  Cyclopedia 
of  Agriculture    *    X 

A  Compendium  of  Agricultural  Science  and  Pratlice 
on    Farm,    Orchard    and   Garden    Crops,    and    the 

Feeding  and  Diseases  of  Farm  Animals       • 

'By    EARLEY  VERNON  WILCOX,  Ph.D 
am)  CLARENCE   BEAMAN  SMITH,    M.S 

Associate  Editors  in  the  Office  of  Experiment  Stations,  United  Slates 
Department  of  Agriculture 

r^"W"*lms  is  a  new,  practical,  and  complete  pres- 
£     I    entation  of  the  whole  subject  of  agricul- 
l__ij    ture  in  its  broadest  sense.    It  is  designed 
PM^M)     for  the  use    of  agriculturists  who   de- 
sire up-to-date,  reliable  information  on 
all   matters    pertaining  to   crops   and   stock,  bmt 
more   particularly  for  the   actual  farmer.      The 
volume  contains 

Detailed  directions  for  the  culture  of  every 
important  field,   orchard,   and   garden   crop 

grown  in  America,  together  with  descriptions  of 
their  chief  insect  pests  and  fungous  diseases,  and 
remedies  for  their  control.  It  contains  an  ac- 
count of  modern  methods  in  feeding  and  handling 
all  farm  stock,  including  poultry.  The  diseases 
which  affect  different  farm  animals  and  poultry 
are  described,  and  the  most  recent  remedies  sug- 
gested for  controlling  them. 

Every  bit  of  this  vast  mass  of  new  and  useful 
information  is  authoritative,  practical,  and  easily 
found,  and  no  effort  has  been  spared  to  include 
all  desirable  details.  There  are  between  6,000 
and  7,000  topics  covered  in  these  references,  and 
it  contains  700  royal  8vo  pages  and  nearly  500 
suberb  half-tone  and  other  original  illustrations, 
making  the  most  perfect  Cyclopedia^of  Agricul- 
ture ever  attempted. 


Handsomely  bound  in  cloth.  JS3.5O;   half  morocco 
(*>«ry  jamptitoa.r  ,  f4.5O.  postpaid 


ORANGE  JUDD  COMPANY, 


REGIONAL  LIBRARY  FACILITY 


